pingpong.go

package main

import (
	"fmt"
	"strconv"
	"time"
)

type Ball int

func (b Ball) String() string {
	return strconv.Itoa(int(b))
}

type Player string

func (p Player) Hit(table chan *Ball, b *Ball) {
	*b++
	fmt.Println(p, b)
	table <- b
}

func play(p Player, table chan *Ball) {
	for {
		ball, ok := <-table
		if !ok {
			return
		}

		time.Sleep(time.Millisecond * 100)
		p.Hit(table, ball)
	}
}

func main() {
	table := make(chan *Ball)

	// Setup the game
	go play("pong", table)
	go play("ping", table)

	// Start game by throwing in a ball
	table <- new(Ball)

	// Wait for some time
	time.Sleep(time.Second)

	// Finish the game by catching the ball
	<-table

	// Signal players to exit (clean-up)
	close(table)

	// Confirm all gorutines are done
	time.Sleep(time.Millisecond)
	panic("Check who is still running...")
}

Live code - https://play.golang.org/p/-S8Fy6SVrH

Output:

ping 1
pong 2
ping 3
pong 4
ping 5
pong 6
ping 7
pong 8
ping 9
pong 10
ping 11
pong 12
panic: Check who is still running...

goroutine 1 [running]:
panic(0x1283a0, 0x1040a1f0)
    /usr/local/go/src/runtime/panic.go:481 +0x700
main.main()
    /tmp/sandbox465543296/main.go:56 +0x200