IO::AIO implements asynchronous I/O using whatever means your operating system
supports. It is implemented as an interface to libeio.

Asynchronous means that operations that can normally block your program (e.g.
reading from disk) will be done asynchronously: the operation will still block,
but you can do something else in the meantime. This is extremely useful for
programs that need to stay interactive even when doing heavy I/O (GUI programs,
high performance network servers etc.), but can also be used to easily do
operations in parallel that are normally done sequentially, e.g. stat'ing many
files, which is much faster on a RAID volume or over NFS when you do a number of
stat operations concurrently.

While most of this works on all types of file descriptors (for example sockets),
using these functions on file descriptors that support nonblocking operation
(again, sockets, pipes etc.) is very inefficient. Use an event loop for that
(such as the EV module): IO::AIO will naturally fit into such an event loop
itself.

In addition to asynchronous I/O, this module also exports some rather arcane
interfaces, such as madvise or linux's splice system call, which is why the A in
AIO can also mean advanced.

WWW: https://metacpan.org/release/IO-AIO