SYSTEM FOR DISCRIMINATING AND CONTROLLING PRIORITY OF COMMUNICATION BETWEEN PROCESSES

PURPOSE:To attain processing with priority without using plural reception windows at the receiving side by providing a flag representing the priority to data processing, placing a data having a specific priority as a head of a queue so as to process the data in the order of queue and awaiting this incoming for the processing of only data having the specific priority. CONSTITUTION:When a data A is incoming with a data not incoming for example, an address of a data storage packet 4 is given to an entry 3 of a packet of a data storage packet 4 in place to 0 so far, 0 is given to an entry 5 of the data storage packet 4 because the next data is not incoming. On the other hand, suppose that a priority having a large number of data processing is higher, the priority area of the packet 4 is brought into 1. When a data B having the priority 1 reaches, the entry 5 of the packet 4 points out the next packet 4'. When a data C having the priority 2 arrives further, an address of a packet 4'' of the data C having higher priority is given to the entry 5 of the packet of the process control block 1 and an address of the packet 4 is given to an entry 5'' of the packet 4''.