Method for implementing single threaded optimizations in a potentially multi-threaded environment

• US 7,395,530 B2
• Filed: 08/30/2004
• Issued: 07/01/2008
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Meta Platforms, Inc. (f/k/a Facebook, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Sundaresan, Vijay, Gray-Donald, Trent A., Inglis, Derek B., Stoodley, Kevin A.
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): WANG, JUE S
• Application Number:
  US10/930,032
• Publication Number:
  US 20060048116A1
• Time in Patent Office: 1,401 Days
• Field of Search: 717141-146, 717/148, 717151-161
• 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. A method for implementing single threaded optimizations in a potentially multi-threaded environment, comprising:

examining program code for characteristics indicative of a potential to generate multiple threads;

wherein the examining is performed dynamically as the program code is running allowing the method to be refined;

wherein the method is refined by at least one of reducing a number of situations that prevent single threaded optimizations from being implemented and delaying correction of single threaded optimizations that have been implemented; and

implementing at least one single threaded optimization if the examining reveals that the program code does not have the potential to generate multiple threads, wherein the implementing is correctible if the program code is later revealed to have the potential to generate multiple threads.

2. The method of claim 1, wherein the examining is performed statically before the program is run.

3. The method of claim 1, wherein the examining comprises examining the program code for a thread creation primitive.

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

5. The method of claim 1, wherein the examining comprises examining whether a native thread created by any process of the program code is attached to a JAVA process.

6. The method of claim 1, wherein the implementing comprises desynchronizing the program code if the examining reveals that the program code does not have the potential to generate multiple threads.

7. The method of claim 1, wherein the implementing comprises at least one of:

optimizing globals for the program code if the examining reveals that the program code does not have the potential to generate multiple threads; and

removing the at least one single threaded optimization if the examining is erroneous.

8. A method for implementing single threaded optimizations in a potentially multi-threaded environment, comprising:

dynamically examining program code for characteristics indicative of a potential to generate multiple threads;

wherein performing the examining dynamically allows the method to be refined;

wherein the method is refined by at least one of reducing a number of situations that prevent single threaded optimizations from being implemented and delaying correction of single threaded optimizations that have been implemented;

implementing at least one single threaded optimization if the dynamically examining step reveals that the program code does not have the potential to generate multiple threads; and

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