Abstract: A debugger for aiding in the debugging of multi-threaded program, in response to an event such as, for example, a breakpoint in a thread which has caused an operating system to stop execution of all threads, identifies the thread which contained the breakpoint. After identifying the thread which contained the breakpoint, the debugger enables the operating system to resume execution of the other threads, that is, the threads which did not contain the breakpoint. By allowing the other threads, that is, the threads which did not contain the breakpoint, to continue execution, the debugger's impact on program execution is substantially reduced, particularly for programs which contain a large number of threads.

Abstract: A system is described for controlling co-scheduling of processes in a computer comprising at least one process and a spin daemon. The process, when it is waiting for a flag to change condition, transmits a flag monitor request to the spin daemon and enables itself to be de-scheduled. The spin daemon, after receiving a flag monitor request, monitors the flag and, after the flag changes condition, enables the process to be re-scheduled for execution by the computer. Since the spin daemon can monitor flags for a number of processes, the ones of the processes that are waiting will not need to be executed, allowing other processes that are not just waiting to be processed more often.

Abstract: A communications arrangement is described for facilitating transfer of messages among a plurality of processes in a computer system. The communications arrangement comprises a channel data structure, a status daemon and an exit handler. The channel data structure includes a channel status flag normally having one of a plurality of conditions, and a plurality of storage locations each configured to receive message information. The status daemon is configured to determine the operational status of the processes. The exit handler is configured to, in response to the status daemon determining a predetermined condition in connection with at least one of the processes, condition the channel status flag to another of the conditions, thereby to indicate to the other processes a failure condition in connection with the communications arrangement.

Abstract: A data visualization arrangement for facilitating the display of data items comprising a selected region of an object in a selected one of a plurality of display modes. The arrangement comprises a data object store, an interface, an object region retrieval component and a display. The data object store stores the data object, the data object comprising a plurality of data items in a predetermined organization. The interface receives a region identification for identifying a particular region of the object and a display mode identification. The object region retrieval component retrieves data items from a region of the data object as identified by the region identification received by the interface. Finally, the display receives the data items as retrieved by the object region retrieval mechanism and displays them in the display mode as identified by the display mode identification.

Abstract: A communication arrangement facilitates transfer of messages among a plurality of processes in with a computer, the computer having a memory shared by the processes. The communication arrangement comprises, allocated to each process, a plurality of buffers, and a plurality of postboxes each associated with one of the other processes. Each process includes a message size determination module and a message transfer module. The message size determination module is configured to determine whether a message to be transferred to another process can be accommodated by a postbox.

Abstract: A data visualization arrangement for facilitating the display of data items comprising a selected region of an object in a selected one of a plurality of display modes. The arrangement comprises a data object store, an interface, an object region retrieval component and a display. The data object store stores the data object, the data object comprising a plurality of data items in a predetermined organization. The interface receives a region identification for identifying a particular region of the object and a display mode identification. The object region retrieval component retrieves data items from a region of the data object as identified by the region identification received by the interface. Finally, the display receives the data items as retrieved by the object region retrieval mechanism and displays them in the display mode as identified by the display mode identification.

Abstract: A data visualization arrangement for facilitating the display of data items comprising a selected region of an object in a selected one of a plurality of display modes. The arrangement comprises a data object store, an interface, an object region retrieval component and a display. The data object store stores the data object, the data object comprising a plurality of data items in a predetermined organization. The interface receives a region identification for identifying a particular region of the object and a display mode identification. The object region retrieval component retrieves data items from a region of the data object as identified by the region identification received by the interface. Finally, the display receives the data items as retrieved by the object region retrieval mechanism and displays them in the display mode as identified by the display mode identification.

Abstract: A system for generating a "where graph" for a parallel processing system comprising a parallel processing array controlled by a control processor. The processing array comprises a plurality of processing elements each processing a program comprising a main routine and a plurality of subroutines, the main routine calling at least one subroutine and at least some of said subroutines calling others of said subroutines. The control processor determines a consolidated program routine sequence identifying sequences of routines extending from said main routine to a current routine being processed by said at least some of said processing elements and generates and displays, on, for example, a video display, the program routine sequence in graph form. The graph comprises a plurality of graph nodes, each representing a routine, with the graph nodes being interconnected to depict the consolidated program routine sequence.

Abstract: A parallel program development and processing system includes a parallel program development section and a parallel program execution section. The parallel program development section allows a program developer to develop programs for execution by a parallel computer system using a predetermined set of components which can be selected by the program developer, using a graphical user interface, and linked in a dataflow graph that represents the order of operations to be performed by the program on the data to be processed. After the program developer has developed the graph, the parallel program development section generates executable program code from the instances of the components and their interconnections, for execution by a parallel computer. In the executable program code, instances of the components selected by the program developer form executable objects which are executed by the parallel computer under control of a run-time system that includes an execution control object.

Abstract: A data visualization arrangement facilitates the display of a selected region of a multi-dimensional data object in a selected one of a plurality of display modes. The arrangement comprises a data object store, an interface, an object region retrieval component and a display. The data object store stores the data object, the data object comprising a plurality of data items in a predetermined organization. The interface receives a region identification for identifying a particular region of the object and a display mode identification. The object region retrieval component retrieves data items from a region of the data object as identified by the region identification received by the interface. Finally, the display receives the data items as retrieved by the object region retrieval mechanism and displays them in the display mode as identified by the display mode identification.

Abstract: A debugger for use in connection with a parallel computer including a plurality of processing nodes. The debugger enables the operator to establish a processing node set in response to certain criteria, such as the respective identifications of the processing node and their prior processing under the debugger. The debugger, in response to a processing node set establishment command from the operator, enables each processing node to establish and condition a set membership flag in response to the operator-supplied set membership criteria. The debugger is then responsive to a debugging command from the operator to enable the processing nodes to use their respective set membership flags to condition their execution of the debugging command.

Abstract: An optimizer for optimizing an intermediate representation (IR) tree having multiple nodes. The IR tree represents a partial compilation of a source code. The source code is written using a high level language supporting data parallel processing. According to the present invention, the optimizer optimizes the IR tree by minimizing the number and size of temporary parallel variables in the IR tree. Such minimization optimizes the IR tree because temporary parallel variables require an enormous amount of space in memory.

Abstract: A compiler for compiling a computer program wherein the computer program is adapted for use with a data parallel computer. The compiler comprises an optimizer which optimizes the compiled code. In optimizing the compiled code, the optimizer performs live variable analysis. With regard to performing live variable analysis, the optimizer of the present invention is adapted for use with data parallel languages. Additionally, the optimizer is computationally efficient at compile time. Further, the optimizer operates in an incremental manner.

Abstract: The present invention is directed towards a compiler for processing parallel communication instructions on a data parallel computer. The compiler of the present invention comprises a front end, a middle end, an optimizer, and a back end. The front end constructs a parse tree which includes nodes representative of parallel communication instructions. The middle end generates an intermediate representation (IR) tree from the parse tree. The IR tree includes general parallel communication IR nodes representative of target code to carry out parallel communication with general communication. An efficient parallel communication module of the optimizer replaces general parallel communication IR nodes with grid parallel communication IR nodes where doing so would result in more efficient target code. The grid parallel communication IR nodes represent target code to carry out parallel communication instructions with grid communication. The back end generates target code from the optimized IR tree.