Time Limited Lock Ownership

• US 20100161573A1
• Filed: 12/19/2008
• Published: 06/24/2010
• Est. Priority Date: 12/19/2008
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Chan, Wilson, Zoll, Michael, Pruscino, Angelo
• Granted Patent: US 8,370,318 B2
• Time in Patent Office: Days
• US Class Current: 707/704
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

Described herein are techniques for time limited lock ownership. In one embodiment, in response to receiving a request for a lock on a shared resource, the lock is granted and a lock lease period associated with the lock is established. Then, in response to determining that the lock lease period has expired, one or more lock lease expiration procedures are performed. In many cases, the time limited lock ownership may prevent system hanging, timely detect system deadlocks, and/or improve overall performance of the database.

Claims

1. A computer-implemented method, comprising:

requesting a lock on a shared resource;

in response to receiving a request;

granting said lock on said shared resource to a lock holder, and establishing a lock lease period associated with said lock;

determining that the lock lease period has expired; and

in response to determining that the lock lease period has expired, performing one or more lock lease expiration procedures.

2. The computer-implemented method of claim 1, wherein the lock lease period associated with said lock is established based on information included in the request, information about the lock holder, and information about the shared resource.

3. The computer-implemented method of claim 1, wherein the establishing the lock lease period associated with said lock is performed by the lock holder itself.

4. The computer-implemented method of claim 1, wherein the establishing the lock lease period associated with said lock is performed by an agent servicing the lock requesting process.

5. The computer-implemented method of claim 1, wherein the establishing the lock lease period associated with said lock is performed by a distributed lock manager (DLM).

6. The computer-implemented method of claim 1, wherein determining that the lock lease period has expired and performing one or more lock lease expiration procedures in response to determining that the lock lease period has expired are carried out by the lock holder itself.

7. The computer-implemented method of claim 1, wherein the performing one or more lock lease expiration procedures comprises increasing the lock lease period associated with the lock.

8. The computer-implemented method of claim 1, wherein the performing one or more lock lease expiration procedures comprises terminating the grant of the lock on the shared resource to the lock holder.

9. The computer-implemented method of claim 1, wherein the performing one or more lock lease expiration procedures comprises collecting and storing diagnostic data about the lock holder, the shared resource or other shared resources.

10. The computer-implemented method of claim 1, wherein the performing one or more lock lease expiration procedures comprises renewing the lease and establishing a new lease lock period associated with the lock.

11. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

12. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

13. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

14. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

15. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

16. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

17. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

18. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

19. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.

20. A computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 10.