Patents by Inventor Duncan Stuart Ritchie

Duncan Stuart Ritchie 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: 20170039143
    Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device receives a key that corresponds to the value, where the key used to retrieve the value form the shared memory hash table and the shared memory hash table is written to by a writer and read from by a plurality of readers. In addition, the device retrieves an index from a local values table, where the local values table stores a plurality of indices for one of the plurality of readers and the index is an index into an entry in the shared memory hash table. The device further retrieves the value from the shared memory hash table using the index.
    Type: Application
    Filed: August 3, 2015
    Publication date: February 9, 2017
    Inventors: Duncan Stuart Ritchie, Sebastian Sapa, Peter John Fordham
  • Patent number: 9495114
    Abstract: A method and apparatus of a device that reads and writes data using a shared memory hash table and a lookaside buffer is described. In an exemplary embodiment, a device locates a bucket for the data in a shared memory hash table, where a writer updates the shared memory hash table and a reader that is one of a plurality of readers reads from the shared memory hash table. The device further retrieves an initial value of a version of the bucket. If the initial value of the version is odd, the device copies the data from a lookaside buffer of the writer to a local buffer for the reader, wherein the lookaside buffer stores a copy of the data while the bucket is being modified.
    Type: Grant
    Filed: May 5, 2014
    Date of Patent: November 15, 2016
    Assignee: Arista Networks, Inc.
    Inventors: Hugh W. Holbrook, Duncan Stuart Ritchie, Sebastian Sapa
  • Publication number: 20160253098
    Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device modifies a value in the shared memory hash table, where the value has a corresponding key. The device further stores a notification in a notification queue that indicates the value has changed. In addition, the device invalidates a previous entry in the notification queue that indicates the value has been modified. The device signals to the reader that a notification is ready to be processed.
    Type: Application
    Filed: May 11, 2016
    Publication date: September 1, 2016
    Inventors: Hugh W. Holbrook, Duncan Stuart Ritchie, Sebastian Sapa, Simon Francis Capper
  • Patent number: 9367251
    Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device modifies a value in the shared memory hash table, where the value has a corresponding key. The device further stores a notification in a notification queue that indicates the value has changed. In addition, the device invalidates a previous entry in the notification queue that indicates the value has been modified. The device signals to the reader that a notification is ready to be processed.
    Type: Grant
    Filed: May 5, 2014
    Date of Patent: June 14, 2016
    Assignee: Arista Networks, Inc.
    Inventors: Hugh W. Holbrook, Duncan Stuart Ritchie, Sebastian Sapa, Simon Francis Capper
  • Publication number: 20140359232
    Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device modifies a value in the shared memory hash table, where the value has a corresponding key. The device further stores a notification in a notification queue that indicates the value has changed. In addition, the device invalidates a previous entry in the notification queue that indicates the value has been modified. The device signals to the reader that a notification is ready to be processed.
    Type: Application
    Filed: May 5, 2014
    Publication date: December 4, 2014
    Inventors: Hugh W. Holbrook, Duncan Stuart Ritchie, Sebastian Sapa, Simon Francis Capper
  • Publication number: 20140337593
    Abstract: A method and apparatus of a device that reads and writes data using a shared memory hash table and a lookaside buffer is described. In an exemplary embodiment, a device locates a bucket for the data in a shared memory hash table, where a writer updates the shared memory hash table and a reader that is one of a plurality of readers reads from the shared memory hash table. The device further retrieves an initial value of a version of the bucket. If the initial value of the version is odd, the device copies the data from a lookaside buffer of the writer to a local buffer for the reader, wherein the lookaside buffer stores a copy of the data while the bucket is being modified.
    Type: Application
    Filed: May 5, 2014
    Publication date: November 13, 2014
    Inventors: Hugh W. Holbrook, Duncan Stuart Ritchie, Sebastian Sapa
  • Publication number: 20140304698
    Abstract: A method and/or network system is able to perform an in-service software upgrade (“ISSU”) using virtualization technology while ongoing network service is maintained. After receipt of an upgrade signal such as a command of software upgrade, a new or second virtual machine (“VM”) is created in response to the upgrade signal. After downloading the new version of program to the second VM while maintaining the first version of program running on the first VM, the process for providing network management begins to migrate from the first version of program to the new version of program. The process simultaneously facilitates ISSU for a data-path module such as a line card to convert from the previous version of software to the new version of the software.
    Type: Application
    Filed: May 29, 2014
    Publication date: October 9, 2014
    Applicant: Tellabs Operations, Inc.
    Inventors: Chakravarthi S. Chigurapati, Pawan Uberoy, Somnath Mani, Praveen Madhav, Duncan Stuart Ritchie, Sebastian Sapa
  • Patent number: 8782632
    Abstract: A method and/or network system is able to perform an in-service software upgrade (“ISSU”) using virtualization technology while ongoing network service is maintained. After receipt of an upgrade signal such as a command of software upgrade, a new or second virtual machine (“VM”) is created in response to the upgrade signal. After downloading the new version of program to the second VM while maintaining the first version of program running on the first VM, the process for providing network management begins to migrate from the first version of program to the new version of program. The process simultaneously facilitates ISSU for a data-path module such as a line card to convert from the previous version of software to the new version of the software.
    Type: Grant
    Filed: June 18, 2012
    Date of Patent: July 15, 2014
    Assignee: Tellabs Operations, Inc.
    Inventors: Chakravarthi S. Chigurapati, Pawan Uberoy, Somnath Mani, Praveen Madhav, Duncan Stuart Ritchie, Sebastian Sapa
  • Patent number: 6430638
    Abstract: A method and apparatus for providing selective object locking is provided. First, a lock object is designated. The identity of the lock object is then made available to objects in an object calling hierarchy. The first object invoked by the calling thread obtains a lock on the lock object to protect data associated with the first invoked object. Other objects in the object calling hierarchy can relock the lock object to protect their data. The invention also provides for selective object locking by providing the capability for a calling thread to specify that no object locking is to be preformed, which causes objects invoked by the calling thread to not perform object locking.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: August 6, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Peter B. Kessler, Mark B. Reinhold, Duncan Stuart Ritchie