[Autogenerated] Inter apps can be invoked by software or by hardware one option.
Is to use the end set of instructions for the intel, ad processors.
To invoke a software interact directly using a synchronous,
essentially call However, we're more interested in hardware interrupts.
So here's a very simplified view of how hardware interrupts work
on Windows So let's say we have a processor,
and that processor has a single line,
to receive interact requests called I N T R for interact
requests and then we have a bunch of devices.
We might have disks, network cards, video cards, mice, whatever device.
Is connected, to the system.
Now obviously connecting all these devices directly.
To the C P U would be kind of problematic because if some device
requires some service then it would be very difficult.
To know which device,
was the one requesting the service So instead there is an
intermediary here known as the inter app controller,
and that interact controller.
On the one hand,
is connected to the devices with these lines that are typically known as
RQ zero RQ one and So on this is short for interrupt,
request and then the interp controller,
is the one that notifies the processor of an interrupt.
So let's say we have one of these devices, notifying the interp controller.
Hey, I'd like to say that Something interesting has happened.
For example, maybe this operation has completed,
the inter controller will interrupt the processor,
the processor will acknowledge, that interrupt,
and then It expects a number,
to appear on the database known as the vector number,
that vector number, is provided by the interrupt controller.
The press that interrupt vector number,
and then uses that as an index into a table known as an interrupt
dispatch table where the actual handler should be called.
So this is the general way, these things work.
Obviously the actual way things.
Are working, is much more complex than that We have multiple processors.
In fact, we have uh a global inter app app controller,
and there's these local internet app controllers,
which are In fact, so sort of bundled with the processor.
It's not as simple as this diagram shows,
but this should give you the basic idea Since we're more
interested in the software aspect of interact as,
as to How Windows works in that respect,
and less in the hardware aspect.
I'm not going to dig deeper into that If you're interested,
you can find more resources online.