println! still done!

main.go

package main

import (
	"fmt"
	"os"
	"time"
)

func println(id int, done chan bool, messages <-chan string, result chan int) {
	for message := range messages {
		time.Sleep(1 * time.Second)
		fmt.Println(id, ":", message)
	}
	done <- true
}

func mc() chan string {
	messages := make(chan string, 4)
	return messages
}

func main() {
	messages := mc()
	done := make(chan bool)
	result := make(chan int)
	n := 4

	for w := 1; w <= 4; w++ {
		go println(w, done, messages, result)
	}

	for i := 0; i < 10; i++ {
		select {
		case v := <-result:
			fmt.Println(v)
			os.Exit(0)
		default:
			messages <- fmt.Sprintf("Hello %d", i)
		}
	}
	close(messages)
	for {
		<-done
		if n--; n == 0 {
			fmt.Println("All done")
			os.Exit(1)
		}
	}
}