chan

package main

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

var wg = sync.WaitGroup{}

func dispatch(c chan int, i int) {
    c <- i
}

func receive(c chan int) {
L:
    for {
        select {
        case data := <-c:
            fmt.Println(data)
            wg.Done()
        case <-time.After(time.Second * 5):
            fmt.Println("done")
            break L
        }
    }
}

func main() {
    chan1 := make(chan int, 0)
    for i := 0; i < 100; i++ {
        wg.Add(1)
        go dispatch(chan1, i)
    }
    receive(chan1)
    wg.Wait()
}

可以参考：

• 1 . https://gobyexample.com/waitgroups
• 2 . https://www.cnblogs.com/wangxusummer/p/4229418.html
• 3 . https://stanzhai.site/blog/post/stanzhai/go%E4%B8%BAchannel%E8%AE%BE%E7%BD%AE%E8%B6%85%E6%97%B6%E7%9A%84%E6%AD%A3%E7%A1%AE%E5%A7%BF%E5%8A%BF

注意 退出for select 需在receiver的function里面打个tag