International Business Machines Corporation

Larry K Loucks

Robert John Urquhart

Todd A Smith

Donavon W Johnson

Amal A Shaheen-Gouda

Khoa D Nguyen

Gary Michael Beauregard

Amal Ahmed Shaheen

Thomas James Freund

Richard Ormond Simpson

Hira Advani

Keith E Duvall

Anthony D Hooten

Charles H Sauer

Robert L Wierwille

Nancy L Springen

Chij-Mehn Chang

A system and method for concurrently operating multiple operating system environments on a hardware platform. A dominant personality server is provided to control basic system configuration and resources. Subdominant servers are provided to support applications for other operating systems. Binary compatibility is supported for each dominant and subdominant operating system personality. Personality neutral services are extracted from each operating system environment and coalesced in personality neutral servers. Interprocess communications are implemented using defined object oriented and procedural interfaces. Server response and conflict resolution are handled by the dominant personality neutral server. Any supported operating system can be the dominant server by selection of the operator.

System for multiple co-existing operating system personalities on a

Two polygon fill algorithms are presented for filling polygons on a graphics display. The first polygon fill algorithm fills polygons that are strictly convex. The second polygon fill algorithm fills a larger class of polygons than the first polygon fill algorithm which includes polygons being concave in the x direction, and polygons having crossing lines. The first polygon fill algorithm tests the polygon for strict convexity by testing for a consistent turning direction, and by testing for once around in the y direction. The first polygon fill algorithm then stores the maximum and minimum value of the pel selected by the Bresenham algorithm for each scan line of the polygon. The fill line is drawn from the pel having the minimum value to the pel having the maximum value for each scan line of the polygon. The second polygon fill algorithm tests the polygon to ensure that it can be filled with one unique fill line for each scan line of the polygon. The second polygon fill algorithm stores both a minimum value and maximum value for each scan line of the polygon for each line of the polygon. A fill line is then drawn from the least minimum value to the greatest maximum value for each scan line of the polygon.

Computer program product for utilizing fast polygon fill routines in a

A system and method for controlling access to shared resources in a distributed computer system. Access to shared resources is controlled by a local authorization token manager. Only computer processes holding authorization tokens for the requested operation may perform that operation. Each requested operation checks for the proper token. If the token is not held by the process, it is requested. The local token manager resolves token conflicts before granting tokens. A token manager of a distributed file system export protocol also is able to request authorization tokens from the local token manager. The export protocol token manager controls authorization tokens for that particular distributed file system protocol. Multiple different export protocols may request tokens from the local token manager. The shared resources may therefore be shared by multiple different export protocols without conflict. Local processes and processes requesting shared resource operations through an export protocol that does not itself manage tokens are granted tokens through the operation token request mechanism. This mechanism enables local processes to use shared resources without the performance penalty of having to request through a local distributed client process.

System and method for multi-level token management for distributed file

In a distributed data processing system, the authentication of a process at one node for the use of a service at another node is performed in a facility that is separate from the requestor and service process. The separate facility is also replaceable, thereby allowing different authentication policies to be implemented within the distributed data processing system. The requesting process and the service process merely pass the authentication information between themselves without attempting to interpret the work of the separate authentication facility. In addition to authenticating the requestor to the service, the service is also authenticated to the requestor.

Flexible interface to authentication services in a distributed data

A unique naming system and method are described for managing object identification by a network of computer systems. The naming system employs data structures stored in the memory of the computer systems containing character strings and corresponding addresses to entries in the data structures and objects in the computer systems. Names employed in a particular computer system that correspond to objects in another computer system are resolved by a border data structure capable of transforming names, delimiters and visas across computer systems.

Name resolution for a multisystem network

In a computer system with a screen display on which is formed a plurality of at least partially overlapping windows associated with different applications, a depth buffer is added to the display adapter for providing with different applications, a depth buffer is added to the display adapter for providing clipping assistance to the software-based window manager. A refresh buffer stores pixel data for each pixel of the display. The window manager monitors the current depth position of each of the pixels within the display and generates a depth value for each pixel. In response to an input request for window rearrangement, the window manager assigns a new depth value to each pixel in a window affected by the request, requests that each application affected by the rearrangement to retransmit pixel values for the pixels associated with at least the portion of a affected window which will become visible as a result of the rearrangement, and transmits new depth values for at least the pixels within the affected portions of such windows. The depth buffer receives and compares the new depth values with the current depth value for each pixel. If the comparator determines that the new pixel value has a depth value associated with the same window or a window closer to the viewer, the depth buffer notifies the refresh buffer to store the new pixel values for each of the applications affected by the rearrangement.

Depth buffer clipping for window management

A system for an efficient message handling technique implemented in AIX, an operating system derived from UNIX System V, is described for use in a distributed services network include a plurality of multi-processing, multi-tasking nodes among which interprocess communication occurs via queues, the actual node locations of which are transparent at the application interface.

Interprocess communication queue location transparency

These master system files define the system characteristics that a user at any node in the system can expect to have. The master system files are mounted remotely from each of the nodes of the system and a local copy of the master system files is kept locally reflecting the current contents of the master system file. If a master system file is not available, the local copy is used in read only mode until the node containing the master is available. In addition, each user has its own file tree organization that dictates the necessary remote mounts of directories to enable a user logged on to any node to have the same view of the system that would be obtained from any other node in the system by that user.

Single system image uniquely defining an environment for each user in a

Two polygon fill algorithms are presented for filling polygons on a graphics display. The first polygon fill algorithm fills polygons that are strictly convex. The second polygon fill algorithm fills a larger class of polygons than the first polygon fill algorithm which includes polygons being concave in the x direction, and polygons having crossing lines. The first polygon fill algorithm tests the polygon for strict convexity by testing for a consistent turning direction, and by testing for once around in the y direction. The first polygon fill algorithm then stores the maximum and minimum value of the pel selected by the Bresenham algorithm for each scan line of the polygon. The fill line is drawn from the pel having the minimum value to the pel having the maximum value for each scan line of the polygon. The second polygon fill algorithm tests the polygon to ensure that it can be filled with one unique fill line for each scan line of the polygon. The second polygon fill algorithm stores both a minimum value and maximum value for each scan line line of the polygon for each line of the polygon. A fill line is then drawn from the least minimum value to the greatest maximum value for each scan line of the polygon.

System and method for utilizing fast polygon fill routines in a graphics

A system for, and method of, providing an interface to an application program for accessing networking functions. The application program interface translates routines requesting networking functions to the operating system commands which contain facilities for accessing networking functions. In addition, the application program interface externalizes the operating system commands for use by the application program in accessing networking functions.

Application program interface to networking functions

A method for facilitating the interchange of data in a UNIX* file between two UNIX processes being run concurrently on two virtual machines in a page segmented virtual memory virtual machine type data processing system. A Shared Copy-On-Write (SCOW) command is created for the UNIX type operating system which when executed in response to a system call from one processes causes the specified UNIX file to be mapped to a unique segment of the virtual memory. A map node data structure is established for storing the ID of the unique segment and for maintaining a count value of the number of user sharing the unique segment. A system call to the SCOW command by the second process involving the same UNIX file checks the map node data structure to see if the file is currently mapped for the SCOW mode. Subsequent instructions in the application programs which are run concurrently on the virtual machines operate on the copy of the file in the unique segment so that any data that is changed, i.e. written by one process, is available to be read by the second process.

Method to share copy on write segment for mapped files

An operating system in a digital computer environment is run as a virtual machine on a virtual resource manager. In order to provide a more dynamic environment for the operating system, linkages are made between the operating system device drivers and the corresponding real and virtual devices of the virtual resource manager. This is accomplished by assigning a 'token' to the virtual resource manager. A device dependent information file corresponding to the device is created. This file contains adapter dependent information including a hardward port address for the physical device. The 'token' is placed in the operating system device driver at the time it is initiated. When the operating system device driver is 'opened' to drive the device, it uses the 'token' to communicate with the virtual resource manager device driver thereby accomplishing driver to driver binding. This causes the virtual resource manager device driver to use the adapter dependent information in the special file corresponding to the 'token' and placed in the process stack.

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Austin, TX, United States of America

Larry K Loucks