>io_uring is not an event system at all. io_uring is actually a generic asynchronous syscall facility.

It's not an event system at all! It's an event system!

The type of events being subset of all possible events in system does not make it not events system. Nor it being essentially a queue

It's not an event system in the sense that it's not just a way to get notified when a file descriptor is ready for reading or writing. Like the OP says, it is a way to run syscalls asynchronously.

> It's not an event system in the sense that it's not just a way to get notified when a file descriptor is ready for reading or writing.

first time in my life I hear people calling this an event system. For me it's always been any architecture centered around asynchronous message queues.

Event-Driven Architecture refers to a different thing, but people used to refer to async code as event-based back before async/await existed, when doing async meant writing the Event Loop yourself.

Yes, but "fd readiness checker" is a super narrow nonstandard definition of "event system". Though I get what the author tries to say.