System and program product for implementing single threaded optimizations in a potentially multi-threaded environment

• US 8,201,158 B2
• Filed: 04/09/2008
• Issued: 06/12/2012
• Est. Priority Date: 08/30/2004
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Inglis, Derek B., Gray-Donald, Trent A., Stoodley, Kevin A., Sundaresan, Vijay
• Primary Examiner(s): Bullock, Jr., Lewis A
• Assistant Examiner(s): LOUIE, JUE WANG
• Application Number:
  US12/100,035
• Publication Number:
  US 20080189692A1
• Time in Patent Office: 1,525 Days
• Field of Search: None
• US Class Current: 717/153
• CPC Class Codes: G06F 8/443 Optimisation

Abstract

Under the present invention, program code is examined (statically or dynamically) for characteristics indicative of a potential to generate multiple threads. If none are found, single threaded optimization(s) such as desynchronization, optimization of globals, etc., can be implemented. In addition, if the program code is later revealed to have the potential to generate multiple threads, the single threaded optimization(s) can be corrected to avoid incorrect execution.

Claims

1. An apparatus for implementing single threaded optimizations in a potentially multi-threaded environment, the apparatus comprising:

at least one processor;

a memory coupled to the at least one processor and storing instructions for execution on the at least one processor, the instructions causing the at least one processor to;

examine program code for characteristics indicative of a potential to generate multiple threads, wherein the program code is examined dynamically as the program code is running to at least one of reduce a number of situations that prevent single threaded optimizations from being implemented, and delay correction of single threaded optimizations that have been implemented;

implement at least one single threaded optimization if the characteristics indicate that the program code does not have the potential to generate multiple threads; and

remove the at least one single threaded optimization if the program code is later revealed to have the potential to generate multiple threads.

2. The apparatus of claim 1, wherein the instructions further cause the at least one processor to examine the program code statically as the program code is being compiled.

3. The apparatus of claim 1, wherein examining the program code for characteristics indicative of a potential to generate multiple threads comprises examining the program code for a thread creation primitive.

4. The apparatus of claim 1, wherein examining the program code for characteristics indicative of a potential to generate multiple threads comprises examining a finalizer method in each class that is loaded by the program code.

5. The apparatus of claim 1, wherein examining the program code for characteristics indicative of a potential to generate multiple threads comprises determining whether a native thread created by any process of the program code is attached to a JAVA process.

6. The apparatus of claim 1, wherein implementing at least one single threaded optimization comprises desynchronizing the program code if the characteristics indicate that the program code does not have the potential to generate multiple threads.

7. The apparatus of claim 1, wherein implementing at least one single threaded optimization comprises optimizing globals of the program code if the characteristics indicate that the program code does not have the potential to generate multiple threads.

8. A computer program product for implementing single threaded optimizations in a potentially multi-threaded environment, the computer program product comprising a non-transitory computer-readable storage medium having computer-usable program code embodied therein, the computer-usable program code comprising:

computer-usable program code to examine program code for characteristics indicative of a potential to generate multiple threads, wherein the program code is examined dynamically as the program code is running to at least one of reduce a number of situations that prevent single threaded optimizations from being implemented, and delay correction of single threaded optimizations that have been implemented;

computer-usable program code to implement at least one single threaded optimization if the characteristics indicate that the program code does not have the potential to generate multiple threads; and

computer-usable program code to remove the at least one single threaded optimization if the program code is later revealed to have the potential to generate multiple threads.

9. The computer program product of claim 8, further comprising computer-usable program code to examine the program code statically as the program code is being compiled.

10. The computer program product of claim 8, wherein examining the program code for characteristics indicative of a potential to generate multiple threads comprises examining the program code for a thread creation primitive.

11. The computer program product of claim 8, wherein examining the program code for characteristics indicative of a potential to generate multiple threads comprises examining a finalizer method in each class that is loaded by the program code.

12. The computer program product of claim 8, wherein examining the program code for characteristics indicative of a potential to generate multiple threads comprises determining whether a native thread created by any process of the program code is attached to a JAVA process.

13. The computer program product of claim 8, wherein implementing at least one single threaded optimization comprises desynchronizing the program code if the characteristics indicate that the program code does not have the potential to generate multiple threads.

14. The computer program product of claim 8, wherein implementing at least one single threaded optimization comprises optimizing globals for the program code if the characteristics indicate that the program code does not have the potential to generate multiple threads.

15. A system for implementing single threaded optimizations in a potentially multi-threaded environment, the system comprising:

a code examination system to examine program code for characteristics indicative of a potential to generate multiple threads, wherein the code examination system examines the program code dynamically as the program code is running to at least one of reduce a number of situations that prevent single threaded optimizations from being implemented, and delay correction of single threaded optimizations that have been implemented, wherein the code examination system comprises at least one hardware component;

an optimization system to implement at least one single threaded optimization if the characteristics indicate that the program code does not have the potential to generate multiple threads; and

a review system to remove the at least one single threaded optimization if the program code is later revealed to have the potential to generate multiple threads.

16. The system of claim 15, wherein the code examination system is configured to examine the program code for characteristics indicative of a potential to generate multiple threads by examining the program code for thread creation primitives.

17. The system of claim 15, wherein the code examination system is configured to examine the program code for characteristics indicative of a potential to generate multiple threads by examining finalizer methods in each class that is loaded by the program code.

18. The system of claim 15, wherein the code examination system is configured to examine the program code for characteristics indicative of a potential to generate multiple threads by determining whether native threads created by any process of the program code are attached to a JAVA process.

19. The system of claim 15, wherein the optimization system is configured to implement at least one single threaded optimization by desynchronizing the program code.

20. The system of claim 15, wherein the optimization system is configured to implement at least one single threaded optimization by optimizing globals of the program code.