Abstract: A jack stand apparatus for use with commonly available jacks, particularly for vehicles with insufficient surface area for both jacks and jack stands to be used on the specified lifting points. In one embodiment, the jack stand comprises an axle assembly, a lift pad assembly, a plurality of height adjustable leg assemblies where the leg assemblies may be rotated with respect to the axle assembly, and a leg locking mechanism. In one embodiment, the foldable device is collapsed into a planar orientation, and positioned on top of a jack's lifting plate; passed under the vehicle, including low profile and limited clearance vehicles. Once the apparatus and vehicle are lifted with the jack, the legs of the apparatus are locked into position to support the lifted vehicle, and the jack is safely removed.

Abstract: A system and method for loading a segmented program into a memory for a multitasking data processing system utilizing paged virtual storage for processes is disclosed. A virtual address space having a plurality of pages for the segmented program is established. Segments of the segmented program suitable for packing end to end across page boundaries are identified. A virtual storage object over a contiguous portion of the virtual address space is defined and the segments identified for packing into the virtual storage object are mapped into the contiguous portion. Any segments not suitable for packing across page boundaries start on page boundaries in the virtual address space. Then segments corresponding to selected pages of the virtual address space are demand loaded into frames of the memory in the same manner in which they are addressed into the virtual address space.

Abstract: A method and system for enhancing operating system efficiency in a data processing system by ensuring alignment of stack memory at a multi-byte boundary such that multi-byte data fetch operations may be utilized to efficiently retrieve data from the stack memory. At each invocation of an operating system procedure from an application within a data processing system, a stack memory pointer is examined to determine if stack memory contents including passed parameters and local variables to be allocated onto the stack memory will be aligned at a multi-byte boundary. In response to a prospective nonalignment of local variables, the operating system procedure is recursively invoked with an additional "dummy" parameter, such that stack memory contents will be aligned at a multi-byte boundary. Thereafter, the operating system will automatically align data within the stack memory at a multi-byte boundary so that the data may be efficiently stored and retrieved utilizing multi-byte data operations.

Abstract: A method and apparatus for evaluating software application performance utilizing a compiler application. An evaluation function is created which may be utilized to track and store software application execution information at each invocation thereof. A software application to be evaluated is compiled utilizing a compiler application which inserts at least one prelude routine command during compiling which is utilized to invoke the prelude routine upon each entry to a procedure within the software application. A command invoking the evaluation function is inserted into the prelude routine such that each entry to a procedure within the, software application under evaluation will result in the storage of execution information at that point. In the depicted embodiment of the present invention execution information at each exit from a procedure within the software application is also tracked and stored by invoking the evaluation function automatically prior to returning from a current procedure.

Abstract: A method in a computer system for monitoring time intervals during which external interrupts are inhibited within the computer system in a selected program being run on the computer system. The method and apparatus of the present invention includes identifying a first plurality of instructions, capable of blocking external interrupts and identifying a second plurality of instructions, capable of unblocking external interrupts. After identifying these instructions, a unique benign fault is inserted proximate to selected ones of the first plurality of instructions and selected ones of the second plurality of instructions to produce a special version program. The special version program is then run in the computer system. Faults which occur during the running of the special version program and associated external interrupt-blocking times are monitored.

Abstract: A data processing system has files stored on disks in a tree structure of directories and files. The system is operated to rapidly open files which have been recently opened or for which partial path information is available, by accessing a drive cache in main memory. The cache has entries chained in a tree structure which is then searched to provide the same information during the opening process as that information which would otherwise have to be gotten from a disk. When the cache is full, a new entry replaces the least recently used entry.