DATA HANDLING SYSTEM WITH CIRCULAR QUEUE FORMED IN PAGED MEMORY

A data handling system is provided in which a circular queue formed in paged memory is used to buffer the transfer of data items between a producer entity and a consumer entity. The producer entity maintains a tail pointer into the queue to indicate the storage location next to be written to; similarly, the consumer entity maintains a head pointer to indicate the storage location next to be read. Since the head and tail pointers may point to different memory pages and these may not have been assigned in a contiguous block to the circular queue, the derivation of queue status information using the head and tail pointers is complex. To simplify this task, the producer and consumer entities maintain producer and consumer indexes for the next write and read positions based on a logical view of the queue as a circular continuum of storage locations.