Method and system for scheduling queued messages based on queue delay and queue priority

摘要

Queue processing mechanism in which queued messages are processed based on combination of queue delay and queue priority. A scheduler dequeues the highest priority non-empty Microcode Input Queue (MIQ) to serve the queued messages. If there is no critical queue, meaning that the maximum aging of one or more queues has not been reached, the critical state is not entered. A static weight for each queue is then tested to determine if there is still a message to be processed from the corresponding MIQ. Messages are dequeued from the same MIQ until the static weight is reached. The next MIQ is then served etc., until the queue of the lowest priority level is served. If the critical phase is entered, the status of the normal state is stored for later return and the MIQs in critical state are dequeued according to their critical weights. If other MIQs appear to be critical, they are served in the order of their critical priorities (or weights). The critical queues are dequeued sequentially according to their critical weight. If no critical MIQ is left, the scheduler exits from this critical state and loops back to the normal state that it previously exited. Normal state processing continues until the next critical state occurs.