What is Interrupt handler?
The routine a CPU runs when an interrupt or exception occurs. It saves the interrupted state, handles the cause and returns. Handlers should be kept as short as possible.
Field: OS & Hardware
Interrupt handler in the explanations
While an interrupt handler runs long, other interrupts cannot be serviced and the main code stalls.
What should be avoided inside an interrupt handler?On accepting an interrupt, the CPU saves the address of the instruction it would have executed next plus state such as the operating mode, and jumps to the interrupt handler, located for example via an interrupt vector table.
What is the usual sequence when a CPU accepts an interrupt?When it fires, the CPU always enters the kernel's interrupt handler, so even if a program is stuck in an infinite loop, the OS regains control and can context-switch to another process.
What mechanism mainly lets the OS reclaim the CPU at regula…
Questions that mention Interrupt handler (6)
- While the main code updates a register bit with "reg |= mask;" (read-modify-write), an interrupt handler changes a different bit of the same register. Which pairs the possible problem with a fix correctly?
- What should be avoided inside an interrupt handler?
- Why is it bad practice to kick (reset) the watchdog timer unconditionally inside a 1 ms timer interrupt handler?
- What is the usual sequence when a CPU accepts an interrupt?
- What mechanism mainly lets the OS reclaim the CPU at regular intervals, even from programs that never give it up voluntarily, and switch to other processes?
- When the program above is compiled with optimization, led_on() may never be called even after the timer interrupt fires. Which pairs the cause with the fix correctly?
Related terms
Interrupt Read-modify-write Watchdog timer Microcontroller Interrupt vector table Copy-on-write ASID Context switch Demand paging Device driver