Lock order determination method and system

• US 20070039000A1
• Filed: 08/10/2005
• Published: 02/15/2007
• Est. Priority Date: 08/10/2005
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Co. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Johnson, Robert, Lakshmikantha, Shashi
• Application Number:
  US11/200,031
• Publication Number:
  US 20070039000A1
• Time in Patent Office: Days
• US Class Current: 718/100
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

A lock order determination method and system are described. A thread is executed including an attempt to acquire a lock. The highest lockorder held by a thread prior to attempting to acquire the lock is determined. The lockorder for the lock relative to the determined highest lockorder held is set. The system for determining a lockorder for a lock includes a find lockorder function in a thread of executable instructions arranged to store a lockorder held by the thread accessing the find lockorder function.

Claims

1. A method of determining a lockorder for a lock, comprising:

executing a thread of executable instructions including an attempt to acquire a lock;

determining the highest lockorder held by the thread prior to attempting to acquire the lock; and

setting the lockorder for the lock relative to the determined highest lockorder held.

2. A method as in claim 1, wherein the determining step comprises:

storing the highest lockorder held and a calling point identifier indicative of the location of the attempt to acquire the lock within the executing thread.

3. A method as in claim 1, further comprising:

setting an initial lockorder for the lock prior to executing the thread; and

wherein the setting the lockorder step comprises modifying the initial setting of the lockorder for the lock relative to the determined highest lockorder held.

4. A method as in claim 1, comprising:

repeating the executing and determining steps prior to performing the setting step.

5. A method as in claim 1, wherein the setting step comprises setting the lockorder for the lock to one more than the determined highest lockorder held.

6. A method as in claim 1, wherein the executing step comprises:

setting a new lockorder prior to attempting to acquire the lock.

15. A computer-readable medium storing instructions which, when executed by a processor, cause the processor to implement the method of determining a lock order for a lock as claimed in claim 1.

16. A computer system configured to implement the method of determining a lock order for a lock as claimed in claim 1.

7. A system for determining a lockorder for a lock, comprising:

a find lockorder function in a thread of executable instructions arranged to store a lockorder held by the thread accessing the find lockorder function.

8. A system as in claim 7, wherein the find lockorder function is arranged to store a calling point identifier indicative of the location of the attempt to acquire a lock within the executable instructions.

9. A system as in claim 7, comprising:

a set lockorder function arranged to set the lockorder for the lock relative to the lockorder stored by the find lockorder function.

10. A system as in claim 9, wherein the lockorder set by the set lockorder function is greater than the largest value stored by the find lockorder function.

11. A system as in claim 9, wherein the find lockorder function is arranged to execute one or more times prior to execution of the set lockorder function.

12. A system as in claim 7, comprising:

an initial lockorder set function arranged to set an initial lockorder for the lock prior to executing the thread.

13. A system as in claim 12, comprising:

a set lockorder function arranged to modify the initial lockorder for the lock relative to the lockorder stored by the find lockorder function.

14. A system as in claim 13, wherein the set lockorder function is arranged for execution prior to an acquire new lock function.

17. A lockorder determination system, comprising:

thread execution means for executing a thread of executable instructions including an attempt to acquire a lock; and

lockorder determining means for determining a highest lockorder held by the thread executed by the thread execution means prior to attempting to acquire the lock.

18. A system as in claim 17, wherein the lockorder determining means includes the ability to store a calling point identifier indicative of the location of the attempt to acquire the lock within the executable instructions.

19. A system as in claim 17, comprising:

lockorder setting means for setting the lockorder for the lock to be acquired relative to the lockorder determined by the lockorder determining means.

20. A system as in claim 19, comprising:

lockorder initialization means for setting an initial lockorder for the lock prior to thread execution; and

wherein the lockorder setting means further comprises modifying the initial setting of the lockorder for the lock to be acquired relative to the highest lockorder held determined by the lockorder determining means.