Patents by Inventor Nasser Siddiqi

Nasser Siddiqi 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).

  • Deadlock detection mechanism for data processing system, with doublechecking to confirm that detected deadlock is non-spurious
    Patent number: 6173308
    Abstract: A distributed data processing system has a deadlock detection mechanism for detecting a potential deadlock involving a cyclic chain of dependencies between transactions. The system also has a deadlock doublechecking mechanism for confirming that all the dependencies in the potential deadlock chain are co-existent. If deadlock is confirmed, action is taken to break the deadlock. The deadlock doublechecking mechanism operates by marking the dependencies in the cyclic chain with a unique existence number, and subsequently checking that the existence number of each dependency in the cyclic chain is unchanged. Marking the dependencies may be performed by propagating a probe message, containing a unique probe existence number, and associating this probe existence number with each dependency visited by said marker probe.
    Type: Grant
    Filed: November 15, 1995
    Date of Patent: January 9, 2001
    Assignee: International Computers Limited
    Inventors: Albert Stephen Hilditch, Steve Robert Pettifer, Colin Michael Thomson, Nasser Siddiqi