Patents by Inventor David Mehaffy

David Mehaffy 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).

  • Publication number: 20080059673
    Abstract: A system and method is provided for measuring lock usage in a non-intrusive manner. Measurements are performed only when a lock is contended. When a lock is requested and the lock is available (i.e., is not contended), the only data gathered is a counter that is incremented to keep track of the number of times the particular lock was requested. When a lock is contended, an operating system trace hook is requested. The trace hook records data such as the timestamp that the requester requested the lock, the request count, a stack traceback to identify the function corresponding to the requester, and the address of the lock that was requested. Post-operative processing analyzes the recorded trace hook data to identify contended locks and processes that may not be efficiently using locks.
    Type: Application
    Filed: November 5, 2007
    Publication date: March 6, 2008
    Inventors: David Mehaffy, James Van Fleet
  • Publication number: 20070100826
    Abstract: A method for substantially reducing the latency of the database (DB) logging process by removing the agent notification requirement from the DB logger and allowing the DB logger to proceed to the next commit process without the latency of providing each waiting agent a notification that the agent continue their respective processes. When an agent commits a change to persistent storage of the database, the request is received by the logger, which performs the update to the persistent storage. A list of agents waiting on the completion of the commit process is compiled by the logger. The list of agents is provided to and provided to the next committing agent. The next committing agent then notifies the waiting agents that they are able to proceed with their respective processing. The logger may immediately perform the next update to persistent memory without utilizing a substantial amount of time notifying the waiting agents.
    Type: Application
    Filed: October 27, 2005
    Publication date: May 3, 2007
    Inventors: David Mehaffy, James Van Fleet
  • Publication number: 20070061810
    Abstract: A method and system for providing access to a shared resource utilizing selective locking are disclosed. According to one embodiment, a method is provided comprising receiving a request to perform a resource access operation on a shared resource, invoking a first routine to perform the resource access operation, detecting a data processing system exception generated in response to invoking the first routine, and invoking a second routine to perform the resource access operation in response to such detecting. In the described embodiment, the first routine comprises a dereference instruction to dereference a pointer to memory associated with the shared resource, the second routine comprises a lock acquisition instruction to acquire a global lock associated with the shared resource prior to a performance of the resource access operation and a lock release instruction to release the global lock once resource access operation has been performed.
    Type: Application
    Filed: September 15, 2005
    Publication date: March 15, 2007
    Inventors: David Mehaffy, Greg Mewhinney, Mysore Srinivas
  • Publication number: 20050203904
    Abstract: A system and method is provided for measuring lock usage in a non-intrusive manner. Measurements are performed only when a lock is contended. When a lock is requested and the lock is available (i.e., is not contended), the only data gathered is a counter that is incremented to keep track of the number of times the particular lock was requested. When a lock is contended, an operating system trace hook is requested. The trace hook records data such as the timestamp that the requestor requested the lock, the request count, a stack traceback to identify the function corresponding to the requestor, and the address of the lock that was requested. Post-operative processing analyzes the recorded trace hook data to identify contended locks and processes that may not be efficiently using locks.
    Type: Application
    Filed: March 11, 2004
    Publication date: September 15, 2005
    Applicant: International Business Machines Corporation
    Inventors: David Mehaffy, James Van Fleet