多个协程顺序打印数字

package main

import (
	"sync"
	"fmt"
	"time"
)

var (
	switchFlow chan int
	wg sync.WaitGroup
)

func routine(i int, serialNumber int) {
	time.Sleep(100 * time.Millisecond)
	loop:
	for {
		select {
		case s := <- switchFlow:
			if s == serialNumber  {
				fmt.Println("routine: ", i+1)
				break loop
			} else {
				//fmt.Println("接受到的编号是: ", s)
				switchFlow <- s
			}
		default:
			time.Sleep(10 * time.Millisecond)
		}
	}
	wg.Done()
	switchFlow <- serialNumber+1
}

func main() {
	switchFlow = make(chan int)
	wg.Add(100)
	for i := 0; i < 100; i++ {
		go routine(i, 10+i)
	}
	//引爆点
	switchFlow <- 10

	wg.Wait()
	close(switchFlow)
	fmt.Println("程序结束")
}