Operating System - Device Queue - IO Queue
Device or IO Queue
Device queue contains the processes which are waiting for the completion of I/O request. Each device has its own device queue. Devices usually have device controller hardware and device driver software that work as part of the OS to control it. Many Device drivers have device queues in order to handle IO requests specific to the device. For example, if you type in a sentence using your keyboard, the sentence is received by controller and put on Input queue. This IO queue is read by a driver(part of OS) and put on an input queue. From input data queue, it is moved to the ready queue for CPU processing. The Input requests come from Keyboard, Mouse, touchscreen and other such devices. After CPU processing, output requests are sent to Output device.