All notes
Async

# Asynchronous programming

Good references:

• Async programming vs Multi-threaded programming, handout by Brown University.

select/poll also relies on kernel notification for ready filedeskriptors. But the disadvantage of select/poll is that they block as soon they are called because the Systemcall-Handler runs in the Kernel-Space.

You don't mix epoll with io_submit; they are two completely different methods for doing IO. The former is for use with bsd style non blocking IO, and the latter is truly async io. epoll will signal you whenever a file can be read ( the read ahead buffer is non empty ) or written ( there's memory available to buffer writes ). io_getevents() won't notify you of anything until you actually request a read or write, in which case, it lets you know when that has completed.