Comment by p_ing

IOCP, which originated in NT 3.1, is not a circular buffer like io_uring, but both are completion-oriented.

Microsoft introduced I/O Rings, more or less a 1:1 copy of io_uring, in Windows 21H1.

https://learn.microsoft.com/en-us/windows/win32/api/ioringap...

https://windows-internals.com/i-o-rings-when-one-i-o-operati...

https://windows-internals.com/ioring-vs-io_uring-a-compariso...

Windows 8/2012 R2 did introduce Registered I/O for WinSock which is very similar to I/O Rings and io_uring.

https://learn.microsoft.com/en-us/previous-versions/windows/...