in 2.22.x include:
* GArray, GPtrArray, GByteArray, GTree and GMappedFile can be reference
counted.
* GLib can be forced to reload the XDG user directory mapping.
* The GLib mainloop supports per-thread default contexts.
* GIO now provides types and methods for IP addresses and UNIX domain
socket addresses.
* GResolver provides asynchronous and cancellable APIs for resolving
hostnames, reverse lookup of IP addresses and resolving SRV records.
* Support for network IO has been added to GIO, including low-level
socket API and high-level API for network connections and services.
* GIOStream and its subclasses have gained support for read-write
access.
* GIO supports starting and stopping of drives, which can be used
in connection with external hard disk enclosures, disk arrays, iSCSI
devices, etc.
* GIO supports user interaction during unmount and eject operations.
* GIO can store and retrieve per-file metadata.