PROCESS AND SYSTEM FOR JAVA VIRTUAL METHOD INVOCATION

• US 20020144243A1
• Filed: 06/11/1999
• Published: 10/03/2002
• Est. Priority Date: 06/11/1999
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: ALEXANDER, WILLIAM PRESTON III, GU, WEIMING
• Granted Patent: US 6,507,946 B2
• Time in Patent Office: Days
• US Class Current: 717/140
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution

Abstract

A process and system for optimizing an invocation of a method is provided. A determination is made to compile a calling method, and a call to a callee method is detected within the first method. The callee method may be a non-final, virtual method, and a determination may be made that the callee method has not been previously overridden. The callee method is then inlined within the first method. In addition, no conditional statements are inserted into the calling method along with the inlined method. The determination to compile and optimize these methods may be made by a just-in-time compiler, and if the methods are Java methods, then a Java just-in-time compiler performs the optimization process. If a determination is made to load a class that contains a method that overrides the callee method, then the calling method is recompiled or patched.

Claims

1. A process for optimizing an invocation of a method, the process comprising the computer-implemented steps of:

in response to a determination to compile a first method, detecting an invocation of a second method by the first method; and

inlining the second method in the first method without a conditional statement in the first method for conditional execution of the inlined second method.

2. The process of claim 1 wherein the second method is a non-final, virtual method.

3. The process of claim 1 further comprising:

in response to a determination to load a class comprising a third method that overrides the second method, recompiling or patching the first method.

4. The process of claim 1 further comprising:

determining that the second method has not been previously overridden.

5. A process for optimizing an invocation of a method, the process comprising the computer-implemented steps of:

in response to a determination to compile a first method, detecting a call to a second method within the first method, wherein the second method is a non-final, virtual method; and

inlining the second method within the first method.

6. The process of claim 5 wherein the second method is unconditionally inlined within the first method.

7. The process of claim 5, further comprising:

just-in-time compiling the first method with the inlined second method.

8. The process of claim 5 wherein the first method and the second method are Java methods.

9. The process of claim 5 further comprising:

in response to a determination to load a class comprising a third method that overrides the second method, recompiling or patching the first method.

10. The process of claim 5 further comprising:

determining that the second method has not been previously overridden.

11. The process of claim 5 further comprising:

maintaining a list of dependencies among methods for updating compiled methods that contain inlined methods that may be overridden.

13. The data processing system of claim 12 wherein the second method is unconditionally inlined within the first method.

14. The data processing system of claim 12 further comprising:

compiling means for just-in-time compiling the first method with the inlined second method.

15. The data processing system of claim 12 wherein the first method and the second method are Java methods.

16. The data processing system of claim 12 further comprising:

recompiling means for recompiling, in response to a determination to load a class comprising a third method that overrides the second method, the first method.

17. The data processing system of claim 12 further comprising:

patching means for patching, in response to a determination to load a class comprising a third method that overrides the second method, the first method.

18. The data processing system of claim 12 further comprising:

determining means for determining that the second method has not been previously overridden.

19. The data processing system of claim 12 further comprising:

maintaining means for maintaining a list of dependencies among methods for updating compiled methods that contain inlined methods that may be overridden.

12. A data processing system for optimizing an invocation of a method, the data processing system comprising:

detecting means for detecting, in response to a determination to compile a first method, a call to a second method within the first method, wherein the second method is a non-final, virtual method; and

inlining means for inlining the second method within the first method.

20. A computer program product in a computer-readable medium for use in a data processing system for optimizing an invocation of a method, the computer program product comprising:

instructions for detecting, in response to a determination to compile a first method, a call to a second method within the first method, wherein the second method is a non-final, virtual method; and

instructions for inlining the second method within the first method.

21. The computer program product of claim 20 further comprising:

instructions for updating the first method in response to a determination to load a class comprising a third method that overrides the second method.

22. The computer program product of claim 20 further comprising:

instructions for determining that the second method has not been previously overridden.