Keskeytysmekanismit

Keskeytysmekanismit, or interrupt mechanisms, are fundamental components in computer systems that allow hardware devices or software to signal the central processing unit (CPU) to temporarily stop its current task and attend to a more urgent event. When an interrupt occurs, the CPU suspends the execution of the current program and jumps to a predefined interrupt handler routine. This routine is responsible for processing the interrupt, such as acknowledging the device or handling an error. After the interrupt handler finishes, the CPU typically resumes the interrupted program from where it left off.

There are two main types of interrupts: hardware interrupts and software interrupts. Hardware interrupts are generated by physical devices, like a keyboard press or a mouse click, or by a timer reaching a specific point. Software interrupts, on the other hand, are triggered by instructions within a program, often used for requesting services from the operating system, such as file input/output operations.

The interrupt mechanism plays a crucial role in multitasking operating systems, enabling the CPU to efficiently switch between different processes and respond to external events in real-time. Without interrupts, the CPU would have to constantly poll devices to check for new input or events, which would be highly inefficient. The ability to handle interrupts allows for responsive and dynamic system behavior. Interrupts can also be prioritized, meaning that more critical interrupts can interrupt less critical ones, ensuring that urgent tasks are handled promptly.