Make multiple queries and return the fastest in Go, using goroutines and a buffered channel

query.go

package main

import (
	"fmt"
	"math/rand"
	"strings"
	"time"
)

// multiQuery uses a buffered channel, otherwise the two slower goroutines
// would get stuck trying to send their responses on a channel from which
// no goroutine will ever receive. This bug is a _goroutine leak_.
func multiQuery() string {
	responses := make(chan string, 3)
	go func() { responses <- request("asia.example.com") }()
	go func() { responses <- request("us.example.com") }()
	go func() { responses <- request("europe.example.com") }()
	return <-responses // return the quickest response
}

// spoof a very long request
func request(hostname string) (response string) {
	rand.Seed(time.Now().UnixNano())
	time.Sleep(time.Duration(rand.Intn(100000)))

	return strings.Split(hostname, ".")[0]
}

func main() {
	fmt.Printf("%s returned first\n", multiQuery())
}