| 摘要 |
<p>In a data processing system, the flow of messages specifying the states of various processes in the system, is regulated using a first register which maintains a list of the current states of each process, and a queue. Whenever a process state message relating to a particular process arrives, the new state of that process is written into the current state register, and an item is placed in a queue. The item indicates the identity of the process concerned. When the item reaches the front of the queue, the current state of the process it identifies is read from the current state register and used to generate an output message. Flags can be used to reduce the redundancy of items in the queue and limit its size. The queue can be modified to cope with messages of differing priorities. To reduce memory requirements, the processes may be grouped into sets, so that each queue item relates to a set of processes.</p> |
