Automatic Server Reloading in Rust on Change: What Is Listenfd/Systemfd?

[ingve]

https://lucumr.pocoo.org/2025/1/19/what-is-systemfd/

[josephcsible]

Those names made me expect a new OS primitive like signalfd/eventfd/timerfd/userfaultfd, but that's not what they are at all.

[the_mitsuhiko → josephcsible]

Indeed. That's just my pretty terrible skills for naming striking again. "systemfd" is supposed to be a pun on "systemd" since the socket activation protocol is basically the same, and "listenfd" is supposed to mean "listen from an fd passed".