Updating spin counters for spin latches

• US 7,174,404 B2
• Filed: 11/07/2002
• Issued: 02/06/2007
• Est. Priority Date: 03/01/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Huras, Matthew A., Stocker, Russell M., Evans, Dominque J., Limoges, Joseph Serge
• Primary Examiner(s): Perveen; Rehana
• Assistant Examiner(s): KNOLL, CLIFFORD H
• Application Number:
  US10/290,384
• Publication Number:
  US 20030182356A1
• Time in Patent Office: 1,552 Days
• Field of Search: 710/200, 710/220, 707/8, 707/9, 718/103, 711/158
• US Class Current: 710/200
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A spin counter updating system and method for updating spin counters for spin latches in a multiprocessor computing system. The updating system includes main spin counter value storage for storing spin counter data correlated to at least one spin counter value, and a master agent. The master agent includes agent spin counter value storage for storing spin counter data correlated to at least one spin counter value; and a spin counter signal handler, wherein the spin counter signal handler is adapted to read spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage.

Claims

1. A spin counter updating system for updating spin counters for spin latches in a multiprocessor computing system, the updating system comprising:

(a) main spin counter value storage for storing spin counter data correlated to at least one spin counter value;

(b) a master agent comprising;

(i) agent spin counter value storage for storing spin counter data correlated to at least one spin counter value; and

(ii) a spin counter signal handler, wherein the spin counter signal handler is adapted to read spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage wherein the spin counter data is for counting.

2. The updating system of claim 1, wherein the spin counter signal handler is configured to respond to a signal call and to read the spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage.

3. The spin counter updating system of claim 1 operatively coupled to a database management system.

4. The updating system of claim 1, wherein the spin counter data comprises outer loop data, inner loop data and waste loop data.

10. The system of claim 1, wherein the master agent is a template used to create child agents, the system further comprising:

a child agent created from the master agent, wherein the child agent includes a child agent spin counter value storage that stores the spin counter data, a child agent spin counter signal handler, and software that is configured to access a resource.

11. The system of claim 10, wherein responsive to the software attempting to access the resource and the resource being locked, the child agent initiates a latch function executing one or more nested loops using the spin counter data stored in the child agent spin counter value storage.

12. The system of claim 10, wherein the child agent spin counter signal handler is configured to respond to a signal call and to read the spin counter data from the main spin counter value storage and to store the read spin counter data to the child agent spin counter value storage.

13. The system of claim 12, wherein the spin counter data comprises an outer loop counter, an inner loop counter, and a waste loop counter.

5. A method of updating spin counters for spin latches in a multiprocessor computing system, the method comprising the following steps:

(a) providing a main spin counter value storage for storing spin counter data correlated to at least one spin counter value;

(b) providing a master agent comprising;

(i) agent spin counter value storage for storing spin counter data correlated to spin counte values; and

(ii) a spin counter signal handler, wherein the spin counter signal handler is adapted to receive a signal call, and wherein upon receiving a signal call, the spin counter signal handler is adapted to read spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage;

(c) creating at least one child agent from the master agent wherein the child agent comprises the spin counter signal handler;

(d) storing updated spin counter data in the main spin counter value storage; and

(e) initiating a signal call to each spin counter signal handler wherein the spin counter data is for counting.

14. The method of claim 5, wherein the spin counter signal handler is configured to respond to a signal call and to read the spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage.

15. The method of claim 5, wherein a given child agent from the at least one child agent is associated with a process initiated by a database management system.

16. The method of claim 5, wherein the spin counter data comprises an outer loop counter, an inner loop counter, and a waste loop counter.

17. The method of claim 5, wherein a given child agent within the at least one child agent includes software that is configured to access a resource.

18. The method of claim 17, wherein responsive to the software attempting to access the resource and the resource being locked, initiating a latch function executing one or more nested loops using the spin counter data stored in the child agent spin counter value storage.

6. A computer program product in a computer readable medium for updating spin counters for spin latches in a multiprocessor computing system, wherein the computer readable medium has a computer readable program, wherein the computer readable program, when executed on the multiprocessor computing system, causes the multiprocessor computing system to:

provide a main spin counter value storage for storing spin counter data correlated to at least one spin counter value;

provide a master agent including;

agent spin counter value storage for storing spin counter data correlated to spin counter values; and

a spin counter signal handler, wherein the spin counter signal handler is adapted to receive a signal call, and wherein upon receiving a signal call, the spin counter signal handler is adapted to read spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage;

create at least one child agent from the master agent wherein the child agent comprises the spin counter signal handler;

store updated spin counter data in the main spin counter value storage; and

initiate a signal call to each spin counter signal handler wherein the spin counter data is for counting.

7. The computer program product according to claim 6, wherein the spin counter signal handler is configured to respond to a signal call and to read the spin counter data from the main spin counter value storage and to store the read spin counter data to the agent spin counter value storage.

8. The computer program product according to claim 6 wherein a given child agent from the at least one child agent is associated with a process initiated by a database management system.

9. The computer program product according to claim 6, wherein the spin counter data comprises outer loop data, inner loop data and waste loop data.

19. The computer program product of claim 6, wherein a given child agent within the at least one child agent includes software that is configured to access a resource.

20. The computer program product of claim 19, wherein responsive to the software attempting to access the resource and the resource being locked, the given child agent initiates a latch function executing one or more nested loops using the spin counter data stored in the child agent spin counter value storage.