Abstract: A method of maintaining a count of active events of a process is provided by a start counter and a complete counter. The start counter maintains a first count of start events and may be operated upon only by the start event of the process. The complete counter maintains a second count of complete events and may be operated upon only by the complete event of the process. The count of active events is established by determining the difference between the first and second counts. The present invention further provides for re-setting the first and second counts of the start and complete counters, respectively, when one or both of the counters have reached a maximum count value.

Abstract: A multiprocessor data processing system for handling a plurality of queues within the data processing system. Each queue is associated with a pointer. A first queue is designated as the current queue along with a first pointer associated with the first queue. This first pointer is designated as a current pointer. Entries are read within the current queue using the current pointer. In response to a condition requiring a change in queues, the current pointer is stored and another pointer is designated or loaded for use as the current pointer. Entries are read with the new current pointer within a queue associated with that pointer.

Abstract: A method and apparatus for efficiently posting entries to a queue within the data processing system. Entries are posted by first processor with the entries being handled by second processor in the data processing system. The interrupt state associated with the queue is checked by the first processor. If the interrupt state is clear, then the entry is posted to the queue. This interrupt state is cleared only when all entries have been cleared from the queue by the second processor. In this manner, an efficient posting of entries to the queue may be accomplished.