Refactoring programs for flexible locking

• US 8,869,127 B2
• Filed: 01/03/2011
• Issued: 10/21/2014
• Est. Priority Date: 01/03/2011
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dolby, Julian, Sridharan, Manu, Tip, Frank, Schaefer, Max
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): HEBERT, THEODORE E
• Application Number:
  US12/983,581
• Publication Number:
  US 20120174082A1
• Time in Patent Office: 1,387 Days
• Field of Search: 717/151
• US Class Current: 717/151
• CPC Class Codes: G06F 8/458 Synchronisation, e.g. post-wait, barriers, locks synchronisation among tasks G06F9/52
• CPC Class Codes: G06F 8/72 Code refactoring

Abstract

Disclosed is a novel computer implemented system, on demand service, computer program product and a method that provides a set of lock usages that improves concurrency resulting in execution performance of the software application by reducing lock contention through refactoring. More specifically, disclosed is a method to refactor a software application. The method starts with accessing at least a portion of a software application that can execute in an operating environment where there are more two or more threads of execution. Next, a determination is made if there is at least one lock used in the software application to enforce limits on accessing a resource. In response to determining that there is a lock with a first type of construct with a given set of features, the software application is refactored with the lock to preserve behavior of the software application.

Claims

1. A computer-implemented method to refactor a software application, the computer-implemented method comprising:

executing, with a processor on an information processing system, the following

accessing at least a portion of an original software application that can execute in an operating environment where there are more two or more time-shared threads of execution;

determining if there is at least one lock used in the original software application to enforce limits on accessing a resource;

in response to determining there is at least one lock with a first type of construct with a given set of features, refactoring at least a portion of the original software application with the lock to preserve external functional behavior of a refactored software application such that the refactored software application is functionally equivalent before and after the refactoring for each concurrent user in a set of at least two concurrent users of the refactored software application with the two or more time-shared threads of execution, by

identifying at least one use of the first type of construct for the lock, and further identifying all uses of that first type of construct for the lock in the original software application which must be refactored together in order to preserve external functional behavior in all possible cases;

reassigning the lock to one of a set of lock usages with a second type of construct; and

transforming the lock usages in the first type of construct for the lock that have been identified to the second type of construct for that lock, such that the second type of construct for the lock is always acquired and released whenever the first type of construct for the lock was in the original software application.

2. The computer-implemented method of claim 1, wherein the set of lock usages with the first type of construct includes writes to memory.

3. The computer-implemented method of claim 1, wherein the set of lock usages with the first type of construct includes at least one of an acquire lock and a release lock.

4. The computer-implemented method of claim 1, wherein the set of lock usages with the first type of construct includes local side effects.

5. The computer-implemented method of claim 4, wherein the local side effects includes at least one of an acquire lock, a create new object, a perform write on new object, and a release object.

6. The computer-implemented method of claim 1, wherein the set of lock usages with the first type of construct includes a condition variable.

7. The computer-implemented method of claim 1, wherein the set of lock usages with the second type of construct include use of special features.

8. The computer-implemented method of claim 1, wherein the second type of construct includes at least one read-write lock.

9. The computer-implemented method of claim 1, wherein the set of lock usages with the second type of construct improves concurrency resulting in execution performance of the software application by reducing lock contention.

10. The computer-implemented method of claim 1, wherein the software application is written in the Java programming language.

11. A computer program product to refactor a software application, the computer program product comprising:

a storage medium readable by a computer system, the storage medium storing software programming instructions capable of performing with a processor programming code to carry out;

accessing at least a portion of an original software application that can execute in an operating environment where there are more two or more time-shared threads of execution;

determining if there is at least one lock used in the original software application to enforce limits on accessing a resource;

in response to determining there is at least one lock with a first type of construct with a given set of features, refactoring at least a portion of the original software application with the lock to preserve external functional behavior of a refactored software application such that the refactored software application is functionally equivalent before and after the refactoring for each concurrent user in a set of at least two concurrent users of the refactored software application with the two or more time-shared threads of execution, by

identifying at least one use of the first type of construct for the lock, and further identifying all uses of that first type of construct for the lock in the original software application which must be refactored together in order to preserve external functional behavior in all possible cases;

reassigning the lock to one of a set of lock usages with a second type of construct; and

transforming the lock usages in the first type of construct for the lock that have been identified to the second type of construct for that lock, such that the second type of construct for the lock is always acquired and released whenever the first type of construct for the lock was in the original software application.

12. The computer program product of claim 11, wherein the set of lock usages with the first type of construct includes writes to memory.

13. The computer program product of claim 11, wherein the set of lock usages with the first type of construct includes at least one of an acquire lock and a release lock.

14. The computer program product of claim 11, wherein the set of lock usages with the first type of construct includes local side effects.

15. The computer program product of claim 14, wherein the local side effects includes at least one of an acquire lock, a create new object, a perform write on new object, and a release object.

16. The computer program product of claim 11, wherein the set of lock usages with the first type of construct includes a condition variable.

17. The computer program product of claim 11, wherein the set of lock usages with the second type of construct include use of special features.

18. The computer program product of claim 11, wherein the second type of construct includes at least one read-write lock.

19. The computer program product of claim 11, wherein the set of lock usages with the second type of construct improves concurrency resulting in execution performance of the software application by reducing lock contention.

20. The computer program product of claim 11, wherein the software application is written in the Java programming language.

21. A system to refactor a software application, the system comprising:

a computer memory capable of storing machine instructions; and

a processor in communication with said computer memory, said processor capable of accessing said machine instructions to perform;

accessing at least a portion of an original software application that can execute in an operating environment where there are more two or more time-shared threads of execution;

determining if there is at least one lock used in the original software application to enforce limits on accessing a resource;

in response to determining there is at least one lock with a first type of construct with a given set of features, refactoring at least a portion of the original software application with the lock to preserve external functional behavior of a refactored software application such that the refactored software application is functionally equivalent before and after the refactoring for each concurrent user in a set of at least two concurrent users of the refactored software application with the two or more time-shared threads of execution, by

identifying at least one use of the first type of construct for the lock, and further identifying all uses of that first type of construct for the lock in the original software application which must be refactored together in order to preserve external functional behavior in all possible cases;

reassigning the lock to one of a set of lock usages with a second type of construct; and

transforming the lock usages in the first type of construct for the lock that have been identified to the second type of construct for that lock, such that the second type of construct for the lock is always acquired and released whenever the first type of construct for the lock was in the original software application.

22. The system of claim 21, wherein the set of lock usages with the first type of construct includes writes to memory.

23. The system of claim 21, wherein the set of lock usages with the first type of construct includes at least one of an acquire lock and a release lock.

24. The system of claim 21, wherein the set of lock usages with the first type of construct includes local side effects.

25. The system of claim 24, wherein the local side effects includes at least one of an acquire lock, a create new object, a perform write on new object, and a release object.