System for accessing a space appended to a circular queue after traversing an end of the queue and upon completion copying data back to the queue

Abstract

A circular queue system is implemented using either a 'mirror space' appended to the circular portion of the queue (or buffer) or an 'borrow' space appended to the circular portion of the queue (or buffer). In each implementation, address verification or checking within the queue is not implemented until such time as the read or write portion to the queue has substantially completed. Where the address would normally exceed the physical or logical end address of the circular queue, the ‘mirror space’ or ‘borrow’ space provides sufficient storage to prevent overflow into other valid data. Upon substantial completion of the read or write to the queue (or buffer), the present address of the pointer is determined, and where the circular portion of the queue (or buffer) has been traversed, the data in the ‘mirror space’ is copied into the circular queue (or buffer) and the pointer's address is repositioned to be within the circular queue (or buffer), or for a ‘borrow’ space, the pointer's address is reset to the queue's (or buffer's) physical or logical start address.