Method and apparatus for a compare and swap instruction

Details Method and apparatus for a compare and swap instruction Method and apparatus for a compare and swap instruction

1984-06-27

1986-04-22

Thomas, James D.

Boots, shoes, and leggings

G06F 100

Patent

active

045846405

ABSTRACT:
In a data processing system having linked lists it is useful to be able to add and delete items from such lists while maintaining the integrity of the linked nature of such lists. A new compare and swap instruction provides for effectively simultaneously swapping 2 values which is useful for safely adding and deleting items from linked lists. Prior to the instruction the status of the two value are read at the locations to be swapped. During the instruction these locations are checked again to ensure that no change has occurred at these locations before the instruction performs the swap of the two new values. The instruction then performs the proposed 2 value swap but only if no change has occurred at these two locations where the swap is to be performed.

REFERENCES:
patent: 3972026 (1976-07-01), Waitman et al.
patent: 4041462 (1977-08-01), Davis et al.
patent: 4054945 (1977-10-01), Ichiko et al.
patent: 4281393 (1981-07-01), Gitelman et al.
patent: 4322812 (1982-03-01), Davis et al.
patent: 4403285 (1983-09-01), Kikuchi
patent: 4429360 (1984-01-01), Hoffman et al.
patent: 4497023 (1985-01-01), Moorer

Affiliated with

Also associated with

Rating

Method and apparatus for a compare and swap instruction does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for a compare and swap instruction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for a compare and swap instruction will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1918790