QUEUING ARRANGEMENT

In a data processing or control system, a method and apparatus for scheduling the sequential processing of actions requested by a series of transaction requests where the execution of two or more sequential processing actions is required to honor each request. A single queue is used to store entries corresponding to the transaction requests. A particular entry is not removed from the queue until all the associated processing actions have been completed. An exemplary queue is used for scheduling the processing actions of a series of transaction request entries, each entry requiring the performance of initial processing and final processing. The queue is controlled by three queue indicators such as pointers. A load pointer indicates the location in the queue where the most recent transaction request entry was loaded, an intermediate pointer indicates the location of the transaction request entry for which initial processing was most recently performed, and an unload pointer indicates the location of the transaction request entry for which final processing was most recently performed.