Patents by Inventor Douglas E. Walls

Douglas E. Walls has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6986126
    Abstract: One embodiment of the present invention provides a system that detects violations of type rules in a computer program. The system operates by locating a type casting operation within the computer program, wherein the type casting operation involves a first pointer and a second pointer. The system then checks the type casting operation for a violation of a type rule. If a violation is detected, the system indicates the violation. In one embodiment of the present invention, if the first pointer is defined to be a structure pointer and the second pointer is not defined to be a structure pointer, the system indicates a violation of a type rule. In one embodiment of the present invention, if the first pointer is defined to point to a first structure type and the second pointer is defined to point to a second structure type, the system determines whether the first structure type and the second structure type belong to the same alias group. If not, the system generates an error to indicate a type violation.
    Type: Grant
    Filed: April 13, 2001
    Date of Patent: January 10, 2006
    Assignee: Sun Microsystems, Inc.
    Inventors: Nicolai Kosche, Douglas E. Walls, David D. Pagan
  • Publication number: 20040015902
    Abstract: One embodiment of the present invention provides a system that detects violations of type rules in a computer program. The system operates by locating a type casting operation within the computer program, wherein the type casting operation involves a first pointer and a second pointer. The system then checks the type casting operation for a violation of a type rule. If a violation is detected, the system indicates the violation. In one embodiment of the present invention, if the first pointer is defined to be a structure pointer and the second pointer is not defined to be a structure pointer, the system indicates a violation of a type rule. In one embodiment of the present invention, if the first pointer is defined to point to a first structure type and the second pointer is defined to point to a second structure type, the system determines whether the first structure type and the second structure type belong to the same alias group. If not, the system generates an error to indicate a type violation.
    Type: Application
    Filed: April 13, 2001
    Publication date: January 22, 2004
    Inventors: Nicolai Kosche, Douglas E. Walls, David D. Pagan
  • Patent number: 5822588
    Abstract: The present invention is a system and method for "checking the use of synchronization locks in a multi-threaded computer program" (hereinafter "WARLOCK II"). In Warlock II a set of source code representing a process which includes multiple threads may be annotated by the developer using a "NOTE" macro to describe the desired operation of the locks. This annotated source code is passed to a modified ANSI C compiler which outputs a special file designated a ".ll" file, as for example, file "foo.ll". This special ".ll" file is then processed as input along with other designated ".ll" files which might be related, by a "wlanalyze" program which will check the source code of the target programs in the ".ll" files to determine whether their use of synchronization locks is consistent with the intended use as specified in the annotations.
    Type: Grant
    Filed: June 9, 1995
    Date of Patent: October 13, 1998
    Assignee: Sun Microsystem, Inc.
    Inventors: Nicholas A. Sterling, Steven R. Kleiman, Charles E. Fineman, Douglas E. Walls, Keith H. Bierman