Comment by veqq

> The user space is the easy part. A historical issue defining our computer landscape is that modern kernels try really hard to provide the illusion of a blocking API. You write a file, which takes time then you continue when it’s done. This is smoke and mirrors, this isn’t how hardware works at all! It’s always fire and forget: Write this, here’s a region of memory, wake me up when it’s over. It’s fundamentally asynchronous. The OS provides these thread and process abstractions which make you think the API’s blocking. The horrible side effect’s that language designers get an out of jail card for async programming, they don’t have to think about it! When writing to a file, they don’t need to make sure the bytes aren’t moved during the operation while running something. No, you just bind to the POSIX API and enjoy this blocking world illusion. - Matklad https://alexalejandre.com/interviews/interview-with-matklad/