Managing operation requests using different resources

Patent metadata

Field	Value
Publication number	US-9619285-B2
Application number	US-201313866027-A
Country	US
Kind code	B2
Filing date	Apr 19, 2013
Priority date	Nov 20, 2003
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

Provided is a method for managing operation requests using different resources. In one embodiment, a first queue is provided for operations which utilize a first resource of a first and second resource. A second queue is provided for operations which utilize the second resource. An operation is queued on the first queue until the first resource is acquired. The first resource is released if the second resource is not also acquired. The operation is queued on the second queue when the first resource is acquired but the second resource is not. In addition, the first resource is released until the operation acquires both the first resource and the second resource.

First claim

What is claimed is:

1. A method comprising:
attempting in a first attempt to acquire a first resource for a task requiring both a first resource and a second resource;
enqueuing said task on a first queue if said first attempt to acquire said first resource for said task fails;
acquiring in a second attempt said first resource for said task;
removing said task from said first queue;
attempting in a first attempt to acquire said second resource for said task;
enqueuing said task on a second queue if said first attempt to acquire said second resource for said task fails; and
releasing said first resource for said task if said first attempt to acquire said second resource for said task fails.

2. The method of claim 1 wherein said first task has a first priority, and wherein said first attempt to acquire said first resource fails when a second task having said first priority is enqueued on said first queue.

3. The method of claim 2 wherein said first task has a first priority, said method further comprising:
attempting in a first attempt to acquire said first resource for a third task requiring said first resource and having a second priority higher than said first priority, and
enqueuing said third task on a third queue if said first attempt to acquire said first resource for said third task fails; and
wherein said first attempt to acquire said first resource for said first task fails when said third task having said second priority is enqueued on said third queue.

4. The method of claim 3 wherein said first task has a first priority, and wherein said first attempt to acquire said second resource fails when a fourth task having said first priority is enqueued on said second queue.

5. The method of claim 4 wherein said first task has a first priority, said method further comprising:
attempting in a first attempt to acquire said second resource for a fifth task requiring said second resource and having a second priority higher than said first priority, and
enqueuing said fifth task on a fourth queue if said first attempt to acquire said second resource for said fifth task fails; and
wherein said first attempt to acquire said second resource for said first task fails when said fifth task having said second priority is enqueued on said fourth queue.

6. The method of claim 5 further comprising:
acquiring in a third attempt said first resource for said first task;
attempting to acquire in a second attempt said second resource for said first task; and
releasing said first resource for said first task if said second attempt to acquire said second resource for said task fails.

7. The method of claim 5 further comprising:
acquiring in a third attempt said first resource for said first task;
acquiring in a second attempt said second resource for said first task;
removing said first task from said second queue; and
dispatching said first task to be completed using said first and second resources.

8. The method of claim 7 further comprising:
finding another task enqueued on one of said second and fourth queues for said second resource;
acquiring said first resource for said other task;
attempting to acquire said second resource for said other task;
removing said other task from its queue if said attempt to acquire said second resource for said other task succeeds;
dispatching said other task to be completed using said first and second resources if said attempt to acquire said second resource for said other task succeeds; and
releasing said first resource for said other task if said attempt to acquire said second resource for said other task fails.

9. The method of claim 7 wherein said third attempt is initiated by the second resource becoming free.

10. The method of claim 7 wherein said third attempt is initiated by the first resource becoming free.

11. The method of claim 7 further comprising:
after all tasks have been removed from said second and fourth queues, finding a next task enqueued on one of said first and third queues for said first resource;
acquiring said first resource for said next task;
attempting to acquire said second resource for said next task;
removing said next task from its queue if said attempt to acquire said second resource for said next task succeeds;
dispatching said next task to be completed using said first and second resources if said attempt to acquire said second resource for said next task succeeds; and
releasing said first resource for said next task if said attempt to acquire said second resource for said next task fails.

Assignees

• IBM

Inventors

• Chen Alex
• Bai Angqin
• Harris Jr Theodore T

Classifications

• G06F9/5011 Primary

  the resources being hardware resources other than CPUs, Servers and Terminals · CPC title

• G06F9/524

  Deadlock detection or avoidance · CPC title