Orderable locks for disclaimable locks

• US 9,471,399 B2
• Filed: 06/18/2013
• Issued: 10/18/2016
• Est. Priority Date: 09/08/2010
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Krauss, Kirk J.
• Primary Examiner(s): Rashid, Wissam
• Application Number:
  US13/920,588
• Publication Number:
  US 20130283282A1
• Time in Patent Office: 1,218 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 9/524 Deadlock detection or avoidance
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

Systems and methods of protecting a shared resource in a multi-threaded execution environment in which threads are permitted to transfer control between different software components, for any of which a disclaimable lock having a plurality of orderable locks can be identified. Back out activity can be tracked among a plurality of threads with respect to the disclaimable lock and the shared resource, and reclamation activity among the plurality of threads may be ordered with respect to the disclaimable lock and the shared resource.

Claims

1. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

create an orderable lock for a disclaimable lock in response to a request to release the disclaimable lock, wherein the request is made by a disclaiming thread that holds the disclaimable lock;

instruct the disclaiming thread to release the disclaimable lock when the orderable lock is created;

cause one or more threads that are waiting for the disclaimable lock to attempt to acquire the orderable lock when the disclaimable lock is released;

determine, if the disclaimable lock is not held by a thread, whether a current thread that attempts to acquire the orderable lock is associated with the orderable lock, wherein the current thread is associated with the orderable lock if it is the disclaiming thread; and

grant acquisition of the orderable lock to the current thread if the current thread is associated with the orderable lock.

2. The computer program product of claim 1, wherein the computer usable code, if executed, further causes a computer to designate the orderable lock as a current orderable lock to be acquired.

3. The computer program product of claim 1, wherein the computer usable code, if executed, further causes a computer to store the orderable lock in a list of orderable locks for the disclaimable lock.

4. The computer program product of claim 1, wherein the computer usable code, if executed, further causes a computer to store the orderable lock as a first orderable lock in a list of orderable locks for the disclaimable lock.

5. The computer program product of claim 1, wherein the computer usable code, if executed, further causes a computer to force the current thread to wait for the disclaimable lock to be released by the thread if the disclaimable lock is held by the thread.

6. The computer program product of claim 1, wherein the computer usable code, if executed, further causes a computer to designate another orderable lock as a current orderable lock in a list of orderable locks for the disclaimable lock if the current thread is associated with the orderable lock.

7. The computer program product of claim 1, wherein the computer usable code, if executed, further causes a computer to remove the orderable lock from a list of orderable locks for the disclaimable lock if the current thread is associated with the orderable lock.

8. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

create an orderable lock for a disclaimable lock in response to a request to release the disclaimable lock, wherein the request is made by a disclaiming thread that holds the disclaimable lock;

instruct the disclaiming thread to release the disclaimable lock when the orderable lock is created; and

cause one or more threads that are waiting for the disclaimable lock to attempt to acquire the orderable lock when the disclaimable lock is released.

9. The computer program product of claim 8, wherein the computer usable code, if executed, further causes a computer to designate the orderable lock as a current orderable lock to be acquired.

10. The computer program product of claim 8, wherein the computer usable code, if executed, further causes a computer to store the orderable lock in a list of orderable locks for the disclaimable lock.

11. The computer program product of claim 8, wherein the computer usable code, if executed, further causes a computer to store the orderable lock as a first orderable lock in a list of orderable locks for the disclaimable lock.

12. The computer program product of claim 8, wherein the computer usable code, if executed, further causes a computer to store a recursion count for the disclaiming thread.

13. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

cause one or more threads that are waiting for a disclaimable lock to attempt to acquire an orderable lock when the disclaimable lock is released

determine, if the disclaimable lock is not held by a thread, whether a current thread that attempts to acquire the orderable lock for the disclaimable lock is associated with the orderable lock, wherein the current thread is associated with the orderable lock if it is a disclaiming thread that issued a request to release the disclaimable lock and cause the creation of the orderable lock; and

grant acquisition of the orderable lock to the current thread if the current thread is associated with the orderable lock.

14. The computer program product of claim 13, wherein the computer usable code, if executed, further causes a computer to force the current thread to wait for the disclaimable lock to be released by the thread if the disclaimable lock is held by the thread.

15. The computer program product of claim 13, wherein the computer usable code, if executed, further causes a computer to designate another orderable lock as a current orderable lock in a list of orderable locks for the disclaimable lock if the current thread is associated with the orderable lock.

16. The computer program product of claim 13, wherein the computer usable code, if executed, further causes a computer to remove the orderable lock from a list of orderable locks for the disclaimable lock if the current thread is associated with the orderable lock.

17. The computer program product of claim 13, wherein the computer usable code, if executed, further causes a computer to remove the orderable lock from a list of orderable locks for the disclaimable lock if the current thread is associated with the orderable lock, the orderable lock being a first orderable lock in the list.

18. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

create an orderable lock for a disclaimable lock in response to a request to release the disclaimable lock, wherein the request is made by a disclaiming thread that holds the disclaimable lock;

instruct the disclaiming thread to release the disclaimable lock when the orderable lock is created; and

designate the orderable lock as a current orderable lock to be acquired.

19. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

create an orderable lock for a disclaimable lock in response to a request to release the disclaimable lock, wherein the request is made by a disclaiming thread that holds the disclaimable lock;

instruct the disclaiming thread to release the disclaimable lock when the orderable lock is created; and

store the orderable lock as a first orderable lock in a list of orderable locks for the disclaimable lock.

20. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

create an orderable lock for a disclaimable lock in response to a request to release the disclaimable lock, wherein the request is made by a disclaiming thread that holds the disclaimable lock;

instruct the disclaiming thread to release the disclaimable lock when the orderable lock is created; and

designate another orderable lock as a current orderable lock in a list of orderable locks for the disclaimable lock if a current thread is associated with the orderable lock.

21. A computer program product comprising:

a non-transitory computer readable storage medium; and

computer usable code stored on the non-transitory computer readable storage medium, where, if executed by a processor, the computer usable code causes a computer to;

create an orderable lock for a disclaimable lock in response to a request to release the disclaimable lock, wherein the request is made by a disclaiming thread that holds the disclaimable lock;

instruct the disclaiming thread to release the disclaimable lock when the orderable lock is created; and

remove the orderable lock from a list of orderable locks for the disclaimable lock if a current thread is associated with the orderable lock.