Keskeytyskäsittelijä

A keskeytyskäsittelijä, often translated as interrupt handler or interrupt service routine (ISR), is a specialized software routine that is executed by a computer's central processing unit (CPU) in response to an interrupt signal. Interrupts are signals generated by hardware devices or software events that require immediate attention from the CPU. When an interrupt occurs, the CPU suspends its current execution of instructions, saves its current state, and then transfers control to the appropriate keskeytyskäsittelijä.

The primary function of a keskeytyskäsittelijä is to handle the interrupt event. This typically involves identifying the source of the interrupt, performing the necessary actions to address the request from the interrupting device or event, and then returning control to the interrupted program. For example, a keyboard interrupt might trigger a keskeytyskäsittelijä to read the key pressed and store it in a buffer. A disk controller interrupt could signal that data has been read or written, prompting the handler to process the completed I/O operation.

Keskeytyskäsittelijät are crucial for efficient multitasking and responsiveness in modern operating systems. They allow the CPU to service multiple devices and events without constantly polling each one, which would be highly inefficient. The design and implementation of effective keskeytyskäsittelijät are fundamental to the performance and stability of computer systems. They must be written carefully to be fast and to minimize the time the CPU is occupied with interrupt processing, ensuring that normal program execution can resume quickly.