stop M sender N receiver using one channel

m_sender_n_receiver.go

package main

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

const senderNum = 20
const receiverNum = 7

type t struct {
	i        int
	senderNo int
}

var dataCh = make(chan t, 100)
var stopCh = make(chan struct{})

func main() {
	startReceiver()
	startSender()

	// let sender and receiver run 3 second
	stopSendDataAfterNSecond(3)
	fmt.Println("stop transmit data")

	// block to wait
	time.Sleep(10 * time.Second)
}
func startSender() {
	for i := 0; i < senderNum; i++ {
		go func(i int) {
			for {
				if stopped() {
					fmt.Printf("sender[%d] stop\n", i)
					return
				}
				dataCh <- t{i: rand.Int(), senderNo: i}
				sleepMs(1, 2)
			}
		}(i)
	}
}
func startReceiver() {
	for i := 0; i < receiverNum; i++ {
		go func(i int) {
			for {
				if stopped() {
					for {
						select {
						case result := <-dataCh:
							fmt.Printf("sender stop but data channel still have data, reveiver[%d] get %d from sender[%d]\n", i, result.i, result.senderNo)
						default:
							fmt.Printf("receiver[%d] stop\n", i)
							return
						}
					}
				}
				<-dataCh
				//result := <-dataCh
				//fmt.Printf("reveiver[%d] get %d from sender[%d]\n", i, result.i, result.senderNo)
				sleepMs(0, 10)
			}
		}(i)
	}
}
func stopSendDataAfterNSecond(t int) {
	time.Sleep(time.Duration(t) * time.Second)
	close(stopCh)
}
func stopped() bool {
	select {
	case <-stopCh:
		return true
	default:
		return false
	}
}

func sleepMs(min, max int) {
	t := rand.Intn(max-min) + min
	time.Sleep(time.Duration(t) * time.Millisecond)
}