About interrupt handler

[Kosta Zertsekel]

>> I'm begin to learn the Kernel and i'm reading <<Linux kernel
>> development>>.It says "This is an important point, always keep in mind that
>> all interrupt handler has interrupted other code(possibly even another
>> interrupt handler on a different line)".What i am not able to understand is
>> how a interrupt handler be interrupted ? DID NOT it uninterrupted?
>
> It depends on the architecture and the interrupt controller being
> used, and the driver code itself.
>
> Normally, when an interrupt fires, that particular interrupt will be
> masked and your own handler won't interrupt itself, but you may very
> well be interrupted by other interrupts.

Can you please point out some code for explanation?
--- KostaZ