Managing lock rankings

• US 7,512,748 B1
• Filed: 08/17/2006
• Issued: 03/31/2009
• Est. Priority Date: 08/17/2006
• Status: Expired due to Fees

• Current Assignee: Open Invention Network LLC
• Original Assignee: OSR Open Systems Resources, Inc.
• Inventors: Mason, W. Anthony, Cariddi, Mark J., Viscarola, Peter G., Noone, Scott J.
• Primary Examiner(s): Verbrugge, Kevin
• Application Number:
  US11/505,582
• Time in Patent Office: 957 Days
• Field of Search: None
• US Class Current: 711/151
• CPC Class Codes: G06F 9/524 Deadlock detection or avoidance

Abstract

Methods of monitoring a computer system. The methods may comprise the steps of calculating a first checksum of a data location and receiving a request from an operation running on the computer system for a lock corresponding to the data location. The methods may also comprise the steps of calculating a second checksum of the data location, and generating an indication if the first checksum and the second checksum are not equivalent. Also, methods of detecting a lock ranking violation in a computer system. The methods may comprise the steps of receiving a request from an operation for a first lock associated with a first data storage location and reviewing a list of locks issued to the operation. The methods may also comprise the step of determining whether the operation possesses a lock ranked higher than the first lock.

Claims

1. A method of detecting a lock ranking violation in a computer system, the method comprising:

receiving a request from an operation for a first lock associated with a first data storage location;

reviewing a list of locks issued to the operation; and

determining whether the operation possesses a lock ranked higher than the first lock.

2. The method of claim 1, further comprising issuing the first lock to the operation if the operation does not possess a lock ranked higher than the first lock.

3. The method of claim 1, further comprising generating a report, wherein the report includes information regarding the request.

4. The method of claim 3, wherein the report comprises the list of locks issued to the operation.

5. The method of claim 3, wherein the report comprises a list of locks issued to a second operation active at the time of the request.

6. The method of claim 1, further comprising aborting the operation if the operation possesses a lock ranked higher than the first lock.

7. The method of claim 1, further comprising issuing the first lock to the operation if the operation possesses a lock ranked higher than the first lock.

8. The method of claim 1, further comprising instructing the operation to release any locks that it possessed at the time of the request if the operation possesses a lock ranked higher than the first lock.

9. The method of claim 8, further comprising instructing the operation to reacquire the locks that it possessed at the time of the request.

10. The method of claim 1, wherein determining whether the operation possesses a lock ranked higher than the first lock comprises determining whether, according to a lock ranking, any locks included in the list of locks issued to operation are not properly attained by the operation until after the first lock.

11. The method of claim 10, wherein the lock ranking is predetermined.

12. The method of claim 1, wherein the first data storage location is a memory location.

13. The method of claim 1, wherein the first data storage location is a disk location.

14. The method of claim 1, wherein the first data storage location comprises a single addressable location.

15. The method of claim 1, wherein the first data storage location comprises a plurality of addressable locations.

16. A tangible computer readable medium having instructions thereon that when executed by a processor, cause the processor to perform the steps of:

receiving a request from an operation for a first lock associated with a first data storage location;

reviewing a list of locks issued to the operation; and

determining whether the operation possesses a lock ranked higher than the first lock.