Keskeytysjärjestelmä

Keskeytysjärjestelmä, often translated as interrupt system or interrupt handler in English, is a fundamental concept in computer operating systems and hardware design. It refers to a mechanism that allows hardware devices or software routines to signal the processor that an event requiring immediate attention has occurred. When such an event happens, the processor temporarily suspends its current task, saves its state, and then executes a specific piece of code, known as an interrupt service routine (ISR) or interrupt handler, to deal with the event. Once the ISR is complete, the processor restores its previous state and resumes the interrupted task.

Interrupts are crucial for efficient multitasking and responsiveness. They enable the system to handle diverse events without constantly polling devices, which would be a waste of processing power. Common sources of interrupts include keyboard input, mouse movements, network packet arrivals, disk I/O completion, and timer expirations. Software interrupts can also be generated by programs to request services from the operating system kernel, such as memory allocation or file access.

The Keskeytysjärjestelmä involves several components: the interrupt controller, which prioritizes and routes interrupts; the interrupt vector table, which stores the addresses of the ISRs; and the ISRs themselves, which are specialized routines designed to handle specific interrupt types. Proper management of interrupts is vital for system stability and performance, as poorly written ISRs can lead to system crashes or performance degradation.