This module implements asynchronous I/O using whatever means your
operating system supports.
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(Only the first 15 lines of the commit message are shown above )