Understanding The Stabilized, High-Performance SD-Bus Of Systemd 221

With today's release of systemd 221 besides enabling KDBUS support being compiled in unconditionally, it also stabilizes the new SD-BUS.

SD-BUS as of systemd 221 is now declared stable and an official interface of libsystemd. As explained in the release announcement, "sd-bus implements an alternative D-Bus client library, that is relatively easy to use, very efficient and supports both classic D-Bus as well as kdbus as transport backend. sd-event is a generic event loop abstraction that is built around Linux epoll, but adds features such as event prioritization or efficient timer handling. Both APIs are good choices for C programs looking for a bus and/or event loop implementation that is minimal and does not have to be portable to other kernels."

Lennart Poettering went on to describe SD-BUS in a new blog post. This SD-BUS library works with both traditional D-Bus and KDBUS. Besides supporting multiple back-ends, Lennart claims that this minimal library performs "substantially better" than libdbus and GDBus. This new blog post is quite lengthy and goes over all of the details for those interested.