[dmitrygr]

Default in linux is read()/write() and be blocked. Doing async is a lot more work and until relatively (to NT timelines) recently quite limited (select).

On NT the standard way is async, and doing things in the block-and-wait way is abnormal and unusual.

Defaults matter. Because that's what most people will do.

[cheph]

Linux use read(2)/write(2) for both blocking and non-blocking. Still don't understand what you mean by how NT does it. Either your code is written to accomodate Async IO or not.