Abstract: A system for controlling a branch history table in a data processing apparatus which has a memory for storing a branch instruction address and a branch destination address corresponding to the branch instruction in a one-to-one correspondence as the branch history table and which employs a virtual storage scheme includes a first register, a second register, a comparator, and a controller. The first register stores the branch instruction address including a virtual space number. The second register stores the branch destination address including the branch virtual space number. The comparator compares the virtual space numbers stored in the first and second registers. The controller enables storage of the branch history table in the memory when a coincidence is established as a result of comparison.

Abstract: Method for centralized monitoring of activity in a distributed processing system which permits a monitor to decipher the relative time sequence of events which occur in the distributed processing system. The method includes the step of generating information which can be used to decipher the relative time sequence of events, which information is appended to activity status messages, and the step of transmitting this information, along with the activity status messages, to the monitor.

Abstract: A logically partitioned data processing system has a policy defining responsive actions to be undertaken by a process in one partition because of a monitored failure of an operating system in another partition. When such a failure occurs, the monitoring partition, if authorized, automatically communicates with a hypervisor to initiate the responsive actions on the failing partitions to reset and/or reconfigure that failing partition. Communication of action request between the partition and the hypervisor is accomplished without operator intervention, through a Service Call Logical Processor interface.

Abstract: A method and apparatus providing for the interaction of processes in an object-oriented manner by which a system manages "classes" of data instances and applications rather than managing the data itself. The names of classes may be stored in a data base which also contains other information about the classes, such as certain con, non attributes of applications or instances which are supported by the classes. Applications can remotely invoke other applications by sending messages with parameters. Using the message names, as well as information about the classes of certain parameters and certain preference information, a reference to a specific method is selected from the data base. That method will perform the operation specified in the message. Other information in the data base is then used to locate and execute the actual code to implement the referenced method.

Abstract: Data processing systems often include multiple servers which provide facilities for other data stations within the system. A File System Driver loaded within an operating system is generally utilized to define the relationships among the operating system, the file systems and the device drivers. The method and system of the present invention loads multiple File System Drivers, each having a public entry point which may be utilized to identify each server device managed by an associated File System Driver. Thereafter, any server request by the user will result in an automatic sequential polling of each loaded File System Driver to identify the particular File System Driver which manages the server in question. In response to a failure to identify the particular File System Driver which manages the desired server, each File System Driver is polled a second time and permitted to transmit queries throughout the system to locate the desired server.

Abstract: On a tightly coupled multiprocessor computer system, the multiple parallel regions of a multithreaded applications program can execute simultaneously as multiple threads on a plurality of processors. Furthermore, a plurality of multithreaded programs may run simultaneously. The current invention uses an efficient system to schedule and reschedule processors to run these multiple threads. Scheduling is integrated at two levels: at the first level, processors are assigned processes. At the next level, processes are assigned threads. Increased efficiency is achieved by this integration and also by the formation of processes with destructible context. It makes use of shared storage to indicate the process request level and the control state for each parallel region.

Abstract: A recalculation function operates in both directions on a spreadsheet. The function is activated when a user directly changes any cell value. The other cell values are automatically recalculated resulting in easier and smoother operation of the spreadsheet.

Abstract: An apparatus is provided for passing respective messages from at least one writer process to multiple respective readers processes comprising: a storage buffer for storing a sequence of respective messages; and an access mechanism for providing respective multiple points of access for the respective reader processes to the sequence of respective messages; wherein for each of the multiple points of access, the access mechanism sequentially provides access to the respective messages of the sequence.

Abstract: A method and system for providing a user with interactive control of device driver configuration. In a preferred embodiment, during configuration of a device driver composed of multiple component drivers, each of a plurality of available component drivers is invoked for potential inclusion in the device driver. For each available component driver, a component driver definition file is provided which contains definition statements. Also for each available component driver, an entry in a parameter registry is provided which contains a list of configuration parameters to be passed to the available component driver when it is invoked. Upon user selection of a component driver, the corresponding component driver definition file is read and the definition statements from the corresponding component driver definition file are provided to the user.

Abstract: A heterogeneous configuration management tool enables building of a software system in a heterogeneous network of computers. In building a desired software system, the tool enables at least one component of the system to be translated by a foreign computer of the network and other components of the system to be translated by other computers of the network. A reference to a version indicator is passed to the foreign computer to provide the foreign computer an indication of user-specified version of the component being translated by the foreign computer. The reference is expanded during processing on the foreign computer. Pathname transformation files are employed to provide transformation of a pathname in one computer of the network to a corresponding pathname in another computer of a network. Binaries resulting from component translations are stored in split pools. In turn, split releases of the built software system are enabled.

Abstract: A compiler-linker software system translates a source code file into a machine executable code file. The compiler converts source code files to corresponding object code files. The linker converts the object code files to machine executable code files and tables required for execution. For each procedure, the linker derives one or more tables and one of the tables is a line number table. The line number table identifies the offset of a block of machine executable codes in the procedure with their corresponding source code line number. The construction of the line number table at link-time, not at compile-time, enables all changes to the sequences of machine executable codes and addresses to be accommodated without requiring supplemental processing of the line number table.

Abstract: A digital computer system includes at least one process, an input/output subsystem, and an input/output interface. The process which input/output requests and receives input/output responses. The input/output system perform input/output operations and generates completion notifications in response thereto. The input/output interface generates input/output responses for the process in the order in which the process issued the input/output requests, to reduce the possibility of the process obtaining information from the order in which the input/output system processed input/output requests.

Abstract: A system of the present invention includes a development system having a language compiler for generating application and system software from source listings. The system includes an Integrated Development Environment having a browser. Methods of the present invention include inspecting symbols (e.g., classes, objects, methods, variables, and the like) dynamically, i.e., while retaining active scope of the symbol. More particularly, the browser of the present invention directly references symbol information stored in object code or executable modules, which are generated during compilation of the source listings. In this manner, the system provides symbol information directly relevant to the context (location in source listing) the user/programmer is currently working.

Abstract: A controller of the type used in process control includes a plurality of modular I/O units. The I/O units includes I/O circuits which may be of four basic types: digital input circuits, digital output circuit, analog input circuits and analog output circuits. The controller is microprocessor-controlled and has an operating system that controls the performance of a number of tasks relating to the control of a plurality of I/O devices to which the controller is connected. Each of the tasks is allocated to one of a plurality of successive time slots, and each task is performed during its associated time slot. The controller includes a priority routine for determining which of the tasks should be performed in each of the time slots. If a task is not completely performed during the time slot to which the task is allocated, the current status of the task is saved to memory so that the task can be completed during a subsequent time slot.

Abstract: A method and apparatus for scoped interprocess message switching between a sender process and a plurality of receiver processes is disclosed. Messages supported may be scoped to message scopes of a message scope type of "Session" or one of a plurality of non-session message scope types including a message scope type of "File". Messages may also be scoped to message scopes of an intersection or union of message scope types. Intersection and union of message scope types comprise "File in Session" and "File or Session". Scoped messages supported further comprise request and notice messages. Receiver processes supported comprise handler processes and observer processes. Request messages may be observed as well as handled, and notice messages may be handled as well as observed. Handler and observer processes may be non-executing as well as executing. Local receiver processes are selected for session scoped messages. Remote as well as local receiver processes are selected for non-session scoped messages.

Abstract: A method for executing a query comprising a sequence of operations to be performed on one or more relational databases comprises statistically sampling the relational databases at the times the operations are to be executed and then dynamically optimizing the performance of the operations based on the statistical samples obtained as a result of the sampling step.

Abstract: A method and apparatus for providing asynchronous communication between at least one central processing unit (CPU) and at least one associated memory unit with specially programmed timing signals to latch, select and transmit data between them.

Abstract: A method of searching the directory of a database, held in the store of an information processing system, to identify an entry in the directory which most closely matches a search entry, each of said directory entries containing first, second and third fields, said search entry containing at least a first field, and each of said fields having the capability of including multiple parts: wherein the set of all directory entries which have the first part of the first field thereof the same as the first part of the first field of the search entry are retrieved from the directory; wherein all parts of the first field of each entry of said set are compared with a similar number of parts of the search entry and according to the degree of match of such comparison, a respective value is calculated for such degree of match; wherein similar comparisons are made between the second and third fields, if any, of each entry of the set and the search entry; and wherein the highest of such calculated values indicates the direc

Abstract: A data management method and system for classifying shared data as new data or past data where the new data may be updated by processing and the past data may not be updated by processing. The data management method and system has a concurrency control, a central control and a sharing of data by a plurality of users wherein the past data is no subject to updating hereby precluding the need for lock processing by concurrency control of past data. In addition, together with query language, the capability of processing new and past data separately allows for an increase of concurrency control efficiency and a smoother user operation.

Abstract: A method for a computer compiler for an object-oriented programming language for implementing virtual functions is provided. In preferred embodiments of the present invention, the virtual function table for a class contains a tile table and a plurality of sub-tables. The tile table contains pointers to the sub-tables, and the sub-tables contain pointers to the virtual function members of the class. Each child class shares a sub-table of the parent class when the child class does not override a function in that sub-table. If the child class overrides a function, then the child is allocated its own sub-table. Each virtual function member for a class is identified by a tile table offset and a sub-table offset.