Accessing return values and exceptions

• US 7,496,896 B2
• Filed: 07/17/2003
• Issued: 02/24/2009
• Est. Priority Date: 07/17/2003
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Inventors: Puryear, Daryl L., Bley, John B.
• Primary Examiner(s): Zhen; Wei Y
• Assistant Examiner(s): CHOW, CHIH CHING
• Application Number:
  US10/622,022
• Publication Number:
  US 20050015750A1
• Time in Patent Office: 2,049 Days
• Field of Search: 717/130, 717/106, 717/127, 712/228, 712/244
• US Class Current: 717/127
• CPC Class Codes: G06F 8/71 Version control security arrangements therefor G06F21/57; Configuration management

Abstract

One or more new methods are added to existing object code. The existing object code includes a first method that is capable of producing a result. New code is added to the first method. The new code provides the result to one or more of the new methods. After the modification, the result (e.g. a return value or exception) from the first method can be accessed and used by other threads, processes, systems, entities etc. that were not originally programmed to access the result or exception.

Claims

1. A method for adding functionality in order to access information, comprising:

accessing existing object code of a first application, said existing object code includes a first method, said first method produces a result when said first method is executed, said existing object code is not configured to provide access to said result by an additional method for which such access is desired;

editing said existing object code to provide modified object code which provides access to said result by said additional method when said first method is executed; and

executing said modified object codes;

said editing comprises modifying said existing object code for;

storing said result, said result is from an operand stack;

preparing said operand stack for an invocation of said additional method;

invoking said additional method, including providing said result to said additional method; and

resetting said operand stack with respect to said result to a state existing prior to said step of storing said result.

2. A method according to claim 1, wherein:

said result includes a data item to be returned by said first method.

3. A method according to claim 1, wherein:

said result includes a reference to an exception.

4. A method according to claim 1, wherein said step of editing includes:

adding code that jumps to a subroutine representing a Finally block after invoking said additional method; and

adding code that is to be executed after returning from said subroutine.

5. A method according to claim 1, wherein said step of editing includes:

adding start byte code;

adjusting byte code indices;

adding exit byte code; and

modifying an exception table for said first method.

6. A method according to claim 5, wherein said step of adding exit byte code includes:

adding byte code to report said result and jump to a subroutine representing a Finally block;

adding byte code to report an exception and jump to said subroutine representing said Finally block; and

adding byte code for said subroutine representing said Finally block.

7. A method according to claim 1, wherein said step of editing includes:

adding Try-Finally functionality which is not included in said existing object code.

8. A method according to claim 1, wherein:

said result includes a data item to be returned by said first method.

9. A method according to claim 8, further comprising:

returning said result after said step of resetting.

10. A method according to claim 1, wherein:

said result includes a reference to an exception.

11. A method according to claim 10, further comprising:

throwing said exception after said step of resetting.

12. A method according to claim 1, further comprising:

performing said additional method in response to said step of invoking.

13. A method according to claim 1, further comprising:

performing one or more instructions of said first method prior to said step of storing said result, said step of performing one or more instructions includes generating said result.

14. A method according to claim 1, in, further comprising:

returning said result subsequent to said step of resetting;

jumping to a subroutine representing a Finally block after invoking said additional method and prior to returning said result; and

returning from said subroutine prior to returning said result.

15. A method according to claim 1, wherein

said modified object code comprises byte code which performs said steps of storing, preparing, invoking and resetting.

16. A method according to claim 15, wherein said step of editing includes:

adding start byte code;

adjusting byte code indices;

adding exit byte code; and

modifying an exception table for said first method.

17. A method according to claim 16, wherein said step of adding exit byte code includes:

adding byte code to report said result and jump to a subroutine representing a Finally block;

adding byte code to report an exception and jump to said subroutine representing said Finally block; and

adding byte code for said subroutine representing said Finally block.

18. A method according to claim 15, wherein said step of editing includes:

adding Try-Finally functionality which is not included in byte code for said first method which is modified.

19. A method according to claim 1, further comprising:

performing said additional method, including accessing said result.

20. A method according to claim 1, further comprising:

performing said additional method, including storing said result for use outside of a thread that includes said first method.

21. A method according to claim 1, further comprising:

performing said additional method in response to said step of invoking, said additional method stores said result;

performing one or more instructions of said first method prior to said step of storing said result, said step of performing one or more instructions includes generating said result; and

modifying byte code for said first method to perform said steps of storing, preparing, invoking and resetting.

22. A method according to claim 21, further comprising:

returning said result;

jumping to a subroutine representing a Finally block after invoking said additional method and prior to returning said result; and

returning from said subroutine prior to returning said result.

23. A method according to claim 1, wherein:

said step of editing includes providing a tracer for said first method.

24. A method according to claim 1, wherein:

said step of editing includes providing a timer for said first method.

25. A method according to claim 1, wherein:

said existing object code is object code of an application to be monitored; and

said additional method is part of a monitoring program which monitors execution of said application.

26. A method according to claim 1, wherein:

said existing object code is object code of an application; and

said additional method is part of said application.

27. A method according to claim 1, wherein:

said modified object code is provided without recompiling said existing object code.

28. One or more processor readable storage devices having processor readable code embodied on said processor readable storage devices, said processor readable code for programming one or more processors to perform a method comprising:

accessing existing object code, said existing object code includes a first method, said first method produces a result when said first method is executed, said existing object code is not configured to provide access to said result by an additional method for which such access is desired; and

modifying said existing object code to provide modified object code that, when executed, provides said result to said additional method;

said step of modifying includes;

adding code that stores said result for said first method from an operand stack;

adding code that prepares said operand stack for an invocation of said additional method;

adding code that invokes said additional method, including providing said result to said additional method; and

adding code that resets said operand stack with respect to said result to a state existing prior to storing said result.

29. One or more processor readable storage devices according to claim 28, wherein:

said result is a data item to be returned by said first method.

30. One or more processor readable storage devices according to claim 28, wherein:

said result is a reference to an exception.

31. One or more processor readable storage devices according to claim 28, wherein said step of modifying includes:

adding start byte code;

adjusting byte code indices;

adding exit byte code; and

modifying an exception table for said first method.

32. One or more processor readable storage devices according to claim 31, wherein said step of adding exit byte code includes:

adding byte code to report said result and jump to a subroutine representing a Finally block;

adding byte code to report an exception and jump to said subroutine representing said Finally block; and

adding byte code for said subroutine representing said Finally block.

33. An apparatus that adds functionality in order to access information, comprising:

a communication interface;

a processor readable storage device; and

one or more processors in communication with said processor readable storage device and said communication interface, said one or more processors perform a method comprising;

access existing object code, said existing object code includes a first method, said first method produces a result when said first method is executed, said existing object code is not configured to provide access to said result by an additional method for which such access is desired; and

modifying said existing object code to provide modified object code that, when executed, provides said result to said additional method;

said step of modifying includes;

adding code that stores said result for said first method from an operand stack;

adding code that prepares said operand stack for an invocation of said additional method;

adding code that invokes said additional method including providing said result to said additional method; and

adding code that resets said operand stack with respect to said result to a state existing prior to storing said result.

34. An apparatus according to claim 33, wherein:

said result is a return value or a reference to an exception.

35. An apparatus according to claim 33, wherein said step of modifying includes:

adding start byte code;

adjusting byte code indices;

adding exit byte code; and

modifying an exception table for said first method.

36. An apparatus according to claim 35, wherein said step of adding exit byte code includes:

adding byte code to report said result and jump to a subroutine representing a Finally block;

adding byte code to report an exception and jump to said subroutine representing said Finally block; and

adding byte code for said subroutine representing said Finally block.

37. An apparatus that adds functionality to existing code in order to access information, comprising:

a communication interface;

a processor readable storage device; and

one or more processors in communication with said processor readable storage device and said communication interface, said one or more processors perform a method for modifying byte code for a first method, said byte code is not configured to provide a result to a second method when said second method is invoked, said method comprising;

storing a result for said first method from an operand stack,

preparing said operand stack for an invocation of said second method,

invoking said second method, including providing said result to said second method, and

resetting said operand stack with respect to said result to a state existing prior to said step of storing said result.

38. An apparatus according to claim 37, wherein:

said result is a data item to be returned by said first method or a reference to an exception.

39. An apparatus according to claim 37, wherein said step of modifying includes the steps of:

adding start byte code;

adjusting byte code indices;

adding exit byte code; and

modifying an exception table for said first method.

40. An apparatus according to claim 39, wherein said step of adding exit byte code includes:

adding byte code to report said result and jump to a subroutine representing a Finally block;

adding byte code to report an exception and jump to said subroutine representing said Finally block; and

adding byte code for said subroutine representing said Finally block.