It depends on the driver model of the particular operating system. The interface specification. Possible techniques used are callbacks, memory buffers, interrupts and signaling mechanisms. Driver models may change over OS versions, which is good for business (you will need new hardware). The OS vendor will tell you it is for security, which is probably true but it sucks nonetheless.

Communicating with driver software in both a reliable and a safe way is hard. You want to delegate work to 3rd party software but you do not want that software to do thing you do not want it to do or disrupt the system in any way. So the interface has to be a bit more complicated than it technically needs to be to just work. Trust and/or validation/certification is an issue.

It depends on the driver model of the particular operating system. The interface specification. Possible techniques used are callbacks, memory buffers, interrupts and signaling mechanisms. Driver models may change over OS versions, which is good for business (you will need new hardware). The OS vendor will tell you it is for security, which is probably true but it sucks nonetheless.

Communicating with driver software in both a reliable and a safe way is hard. You want to delegate work to 3rd party software but you do not want that software to do things you do not want it to do or disrupt the system in any way. So the interface has to be a bit more complicated than it technically needs to be to just work. Trust and/or validation/certification is an issue.