Method and system for identifying instrumentation targets in computer programs related to logical transactions

• US 6,327,700 B1
• Filed: 06/08/1999
• Issued: 12/04/2001
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: Appliant Corporation
• Original Assignee: Appliant Corporation
• Inventors: Chen, J. Bradley, Bershad, Brian N.
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): ZHEN, WEI Y
• Application Number:
  US09/327,697
• Time in Patent Office: 910 Days
• Field of Search: 717/4, 717/9, 702/179, 702/182
• US Class Current: 717/127
• CPC Class Codes: G06F 11/3414 Workload generation, e.g. scripts, playback
• CPC Class Codes: G06F 2201/87 Monitoring of transactions
• CPC Class Codes: G06F 2201/88 Monitoring involving counting

Abstract

A method and system for identifying sets of instructions within a computer program, execution of which serve as an indicator for processing of a transaction by the computer program and that together comprise a witness set. The witness set may be employed to monitor execution of the computer program and detect processing of the transaction. Witness sets are constructed by iteratively filtering an initial set of instructions based on profile data collected during execution of the computer program.

Claims

1. A method for identifying instructions within a program to include in a witness set for a transaction, the method comprising:

constructing a monitor set that includes locations of instructions within the program;

initializing the witness set;

repeatedly

selecting a next profile generated by executing the program to process the transaction a selected number of times, the selected number of times selected from non-negative integers including 0;

selecting a number of instructions from the next profile according to criteria based on execution counts associated with instructions in the next profile; and

using the selected number of instructions to modify the witness set.

2. The method of claim 1 wherein constructing a monitor set that includes locations of instructions within the program further includes:

selecting locations of instructions associated with calling a number of library routines.

3. The method of claim 1 wherein constructing a monitor set that includes locations of instructions within the program further includes:

selecting locations of certain types of instructions.

4. The method of claim 1 wherein, when initialized, the witness set is empty.

5. The method of claim 1 wherein a next profile is generated by executing the program to process the transaction a certain number of times.

6. The method of claim 1 wherein a next profile is generated by executing the program to process the transaction under different conditions, during each execution processing the transaction a number of times.

7. The method of claim 1 wherein selecting a number of instructions from the next profile associated with particular counts further includes:

selecting instructions from the next profile associated with counts equal to the number of times that the transaction was processed during execution of the program, the selected instructions thus correlated with processing of the transaction.

8. The method of claim 1 wherein selecting a number of instructions from the next profile associated with particular counts further includes:

selecting instructions from the next profile associated with counts greater than zero, the transaction not processed during execution of the program and the selected instructions thus correlated with processing other than processing of the transaction.

9. The method of claim 1 wherein using the selected number of instructions to modify the witness set further includes:

including in the modified witness set only those instructions contained in the set intersection of the instructions currently included in the witness set and the selected number of instructions.

10. The method of claim 1 wherein using the selected number of instructions to modify the witness set further includes:

including in the modified witness set only those instructions contained in the set difference between the instructions currently included in the witness set and the selected number of instructions.

11. The method of claim 1 wherein using the selected number of instructions to modify the witness set further includes:

including in the modified witness set only those instructions contained in the set union of the instructions currently included in the witness set and the selected number of instructions.

12. The method of claim 1 wherein the instructions are machine instructions and the program is an executable program.

13. The method of claim 1 wherein the instructions are programming language statements.

14. The method of claim 1 wherein the locations are addresses of machine code instructions within an executable program.

15. The method of claim 1 wherein the locations are symbolic locations within a program.

16. The method of claim 1 further including:

evaluating the quality of the witness set;

when the witness set has a quality lower than a threshold quality,

selecting a new monitor set;

initializing the witness set; and

identifying instructions within the program to include in the witness set by repeatedly

generating a next profile by executing the program to process the transaction;

selecting a number of instructions from the next profile associated with particular counts;

using the selected number of instructions to modify the witness set.

17. The method of claim 16 wherein evaluating the quality of the witness set includes comparing the number of instructions within the witness set to a desired number of instructions.

18. The method of claim 16 wherein evaluating the quality of the witness set includes comparing the distribution of instructions of the witness set within the program to a desired distribution.

19. A witness set prepared by the method of claim 1 stored in a computer readable medium.

20. A witness set prepared by the method of claim 1 stored in a data structure within the memory of a computer.

21. Electronic signals embodied in a carrier wave that encode a representation of a witness set prepared by the method of claim 1.

22. A system for identifying instructions within a program that may compose a witness set, the system comprising:

a program;

a computer on which the program is executed;

a monitor set containing the locations of instructions within the program;

a monitor that monitors execution of the instructions at the locations of instructions contained in the monitor set to generate profiles;

a witness set; and

a witness set generator that repeatedly executes the program, extracts instructions from profiles generated by the monitor, and modifies the witness set by including in the modified witness set instructions resulting from set operations performed on the witness set and the instructions extracted from the profiles.

23. The system of claim 22 wherein the monitor set is a representation of locations of instructions stored in the memory of the computer and includes instructions associated with calling a number of library routines.

24. The system of claim 22 wherein the monitor set is a representation of locations of instructions stored in the memory of the computer and includes locations of certain instructions having particular instruction types.

25. The system of claim 22 wherein the monitor generates a profile while the witness generator executes the program many times under many different conditions.

26. The system of claim 22 wherein the set operations include set intersection, set difference, and set union.

27. Electronic signals embodied in a carrier wave that encode computer instructions that implement the witness set generator of claim 22.

28. A computer-readable medium containing computer instructions that implement the witness set generator of claim 22.