How support concurrent connections with a UDP Server using go - go

Question

I'm playing with my first basic udp server and I wondering how support concurrent connections? I think with my code only can get a connection at a time in order to process it, with a tcp simple server the things seems to be more clear than on this case, throwing a goroutine to process the data, but here I'm very lost, thanks in advance.
func main() {
ListenerUDP("127.0.0.1", 1111)
}
func ListenerUDP(ip string, port int) {
buffer := make([]byte, 1024)
log.Println("Listener Started!")
addr := net.UDPAddr{
Port: port,
IP: net.ParseIP(ip),
}
conn, err := net.ListenUDP("udp", &addr)
if err != nil {
log.Fatalf("Error Listening:%s\n", err.Error())
panic(err)
}
defer conn.Close()
for {
_, remoteAddr, err := conn.ReadFromUDP(buffer[0:])
if err != nil {
log.Fatalf("Error:%s\n", err)
}
// Process data here? using a > go something()?
fmt.Printf("Data:%s From:%v\n", buffer, remoteAddr)
}
}

Answer 1

UDP is a connectionless protocol--hosts send packets without establishing a connection first.
To get multiple cores handling UDP packets in parallel, you might start a bunch of goroutines that each do the ReadFromUDP loop:
package main
import (
"fmt"
"net"
"runtime"
)
func listen(connection *net.UDPConn, quit chan struct{}) {
buffer := make([]byte, 1024)
n, remoteAddr, err := 0, new(net.UDPAddr), error(nil)
for err == nil {
n, remoteAddr, err = connection.ReadFromUDP(buffer)
// you might copy out the contents of the packet here, to
// `var r myapp.Request`, say, and `go handleRequest(r)` (or
// send it down a channel) to free up the listening
// goroutine. you do *need* to copy then, though,
// because you've only made one buffer per listen().
fmt.Println("from", remoteAddr, "-", buffer[:n])
}
fmt.Println("listener failed - ", err)
quit <- struct{}{}
}
func main() {
addr := net.UDPAddr{
Port: 12345,
IP: net.IP{127, 0, 0, 1},
}
connection, err := net.ListenUDP("udp", &addr)
if err != nil {
panic(err)
}
quit := make(chan struct{})
for i := 0; i < runtime.NumCPU(); i++ {
go listen(connection, quit)
}
<-quit // hang until an error
}