Patents by Inventor James W. Van Fleet

James W. Van Fleet 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: 8132178
    Abstract: A system and method is provided for delaying a priority boost of an execution thread. When a thread prepares to enter a critical section of code, such as when the thread utilizes a shared system resource, a user mode accessible data area is updated indicating that the thread is in a critical section and, if the kernel receives a preemption event, the priority boost that the thread should receive. If the kernel receives a preemption event before the thread finishes the critical section, the kernel applies the priority boost on behalf of the thread. Often, the thread will finish the critical section without having to have its priority actually boosted. If the thread does receive an actual priority boost then, after the critical section is finished, the kernel resets the thread's priority to a normal level.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: March 6, 2012
    Assignee: International Business Machines Corporation
    Inventors: Jos Manuel Accapadi, Andrew Dunshea, Dirk Michel, James W. Van Fleet
  • Patent number: 7448036
    Abstract: A system and method for thread scheduling with a weak preemption policy is provided. The scheduler receives requests from newly ready work. The scheduler adds a “preempt value” to the current work's priority so that it is somewhat increased for preemption purposes. The preempt value can be adjusted in order to make it more, or less, difficult for newly ready work to preempt the current work. A “less strict” preemption policy allows current work to complete rather than interrupting the current work and resume it at a later time, thus saving system overhead. Newly ready work that is queued with a better priority than the current work is queued in a favorable position to be executed after the current work is completed but before other work that has been queued with the same priority of the current work.
    Type: Grant
    Filed: May 2, 2002
    Date of Patent: November 4, 2008
    Assignee: International Business Machines Corporation
    Inventors: Larry Bert Brenner, Mysore Sathyanarayana Srinivas, James W. Van Fleet
  • Publication number: 20080271029
    Abstract: Thread scheduling with a weak preemption policy is provided. The scheduler receives requests from newly ready work. The scheduler adds a “preempt value” to the current work's priority so that it is somewhat increased for preemption purposes. The preempt value can be adjusted in order to make it more, or less, difficult for newly ready work to preempt the current work. A “less strict” preemption policy allows current work to complete rather than interrupting the current work and resume it at a later time, thus saving system overhead. Newly ready work that is queued with a better priority than the current work is queued in a favorable position to be executed after the current work is completed but before other work that has been queued with the same priority of the current work.
    Type: Application
    Filed: July 7, 2008
    Publication date: October 30, 2008
    Applicant: International Business Machines Corporation
    Inventors: Larry Bert Brenner, Mysore Sathyanarayana Srinivas, James W. Van Fleet
  • Patent number: 7380247
    Abstract: A system and method is provided for delaying a priority boost of an execution thread. When a thread prepares to enter a critical section of code, such as when the thread utilizes a shared system resource, a user mode accessible data area is updated indicating that the thread is in a critical section and, if the kernel receives a preemption event, the priority boost that the thread should receive. If the kernel receives a preemption event before the thread finishes the critical section, the kernel applies the priority boost on behalf of the thread. Often, the thread will finish the critical section without having to have its priority actually boosted. If the thread does receive an actual priority boost then, after the critical section is finished, the kernel resets the thread's priority to a normal level.
    Type: Grant
    Filed: July 24, 2003
    Date of Patent: May 27, 2008
    Assignee: International Business Machines Corporation
    Inventors: Jos Manuel Accapadi, Andrew Dunshea, Dirk Michel, James W. Van Fleet
  • Patent number: 7278141
    Abstract: A system and method is altering the priority of a process, or thread of execution, when the process acquires a software lock. The priority is altered when the lock is acquired and restored when the process releases the lock. Thread priorities can be altered for every lock being managed by the operating system or can selectively be altered. In addition, the amount of alteration can be individually adjusted so that a process that acquires one lock receive a different priority boost than a process that acquires a different lock. Furthermore, a method of tuning a computer system by adjusting lock priority values is provided.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: October 2, 2007
    Assignee: International Business Machines Corporation
    Inventors: Jos Manuel Accapadi, Andrew Dunshea, Dirk Michel, James W. Van Fleet
  • Publication number: 20040216112
    Abstract: A system and method is altering the priority of a process, or thread of execution, when the process acquires a software lock. The priority is altered when the lock is acquired and restored when the process releases the lock. Thread priorities can be altered for every lock being managed by the operating system or can selectively be altered. In addition, the amount of alteration can be individually adjusted so that a process that acquires one lock receive a different priority boost than a process that acquires a different lock. Furthermore, a method of tuning a computer system by adjusting lock priority values is provided.
    Type: Application
    Filed: April 23, 2003
    Publication date: October 28, 2004
    Applicant: International Business Machines Corporation
    Inventors: Jos Manuel Accapadi, Andrew Dunshea, Dirk Michel, James W. Van Fleet
  • Publication number: 20030208521
    Abstract: A system and method for thread scheduling with a weak preemption policy is provided. The scheduler receives requests from newly ready work. The scheduler adds a “preempt value” to the current work's priority so that it is somewhat increased for preemption purposes. The preempt value can be adjusted in order to make it more, or less, difficult for newly ready work to preempt the current work. A “less strict” preemption policy allows current work to complete rather than interrupting the current work and resume it at a later time, thus saving system overhead. Newly ready work that is queued with a better priority than the current work is queued in a favorable position to be executed after the current work is completed but before other work that has been queued with the same priority of the current work.
    Type: Application
    Filed: May 2, 2002
    Publication date: November 6, 2003
    Applicant: International Business Machines Corporation
    Inventors: Larry Bert Brenner, Mysore Sathyanarayana Srinivas, James W. Van Fleet