[justinsaccount]

Ah, I must have been thinking of something like

https://cr.yp.to/ucspi-tcp/tcpserver.html

[JdeBP]

Then you'll enjoy reading about the nosh toolset and s6-networking, which both separate the listen-accept model into separate programs and have the ability to invoke "wait" servers with the listening socket.

* http://homepage.ntlworld.com./jonathan.deboynepollard/Softwa... * http://homepage.ntlworld.com./jonathan.deboynepollard/FGA/UC... * http://skarnet.org/software/s6-networking/