Interrupthåndtering

Interrupthåndtering, often referred to as interrupt handling, is a crucial mechanism in computer systems that allows hardware or software to signal the CPU to pause its current task and execute a specific routine. This interruption, or interrupt, is a signal that demands immediate attention. When an interrupt occurs, the CPU suspends its ongoing operations, saves the current state of the processor, and then jumps to a predefined location in memory. This location contains the address of the interrupt service routine (ISR), also known as the interrupt handler.

The ISR is a specialized piece of code designed to deal with the specific event that triggered the interrupt. This could range from a user pressing a key on the keyboard, a network card receiving a packet, a disk drive completing a read operation, or a software error. Once the ISR has completed its task, it restores the saved state of the CPU and resumes the interrupted program from where it left off. This process ensures that the system can respond to external events and critical conditions without constantly polling for their status, thereby improving efficiency and responsiveness.

There are typically two main types of interrupts: hardware interrupts and software interrupts. Hardware interrupts are generated by physical devices, such as input/output devices. Software interrupts are triggered by specific instructions within a program, often used for system calls or to signal exceptional conditions. Effective interrupt handling is vital for multitasking operating systems, real-time systems, and any system that needs to interact with the outside world or manage multiple processes efficiently. The order and priority of interrupts are managed by an interrupt controller, ensuring that more critical events are handled first.