| 摘要 |
PURPOSE:To adjust the schedule of I/O devices shared with plural virtual computers and to improve the efficiency of processing the system by giving an inherent waiting time to a subchannel each and preferentially processing queues that exceed a waiting time connected to them. CONSTITUTION:The subchannels 10 and 11 are provided with areas holding the time QTiME connected to the queues and areas holding the threshold WTiME of the previously given waiting time. When the reading of a counter exceeds '1' (when the plural subchannels are connected to the queues), the time that has elapsed after the subchannels were connected to the queues is calculated from the difference between the QTiME of the subchannels and a current time, and it is compared with the WTiME. If it is larger than the WTiME, immediately the I/O device concerned is activated; otherwise, the device is not activated, and the subchannel isolated from the queue is connected to the end of another queue. |
