IoUring async file

[franz1981]

https://github.com/dreamlike-ocean/NettyAsyncFile this looks like a great starting point for a proper async file implementation based on IoUring.

[tsegismont]

Thanks for sharing this @franz1981

There are a some things we need to consider.

First, we'd need to introduce a transport like mechanism because our only implementation has always been based on the JDK (we never had Linux AIO for example).

Then, my understanding is that the JDK's async file channel is truly asynchronous on Windows but not on Linux. Are you aware of any plans from OpenJDK to implement async file channel on top of io_uring for Linux?

Of course, for current jdks that would not work. And having an io_uring async file would allow, for example, piping an AsyncFile to an HttpServerResponse without leaving the event loop.

Any thoughts @vietj ?