tcpKeepAliveListener in go

We can quickly start a http server in go as below.

http.ListenAndServe(":8080", nil)

It is called ListenAndServe because it creates a TCP listener and passes it to the http server.

ln, err := net.Listen("tcp", addr)
srv.Serve(ln)

The actual implementation in the go standard library uses a tcpKeepAliveListener which wraps the TCP listener.

srv.Serve(tcpKeepAliveListener{ln.(*net.TCPListener)})

tcpKeepAliveListener implements the TCP keep-alives which might not be very important because HTTP keep-alives are enabled by default.

SetKeepAlivesEnabled controls whether HTTP keep-alives are enabled. 
By default, keep-alives are always enabled.