實(shí)現(xiàn)方式：用map[int]func(uin32)來實(shí)現(xiàn)，將要執(zhí)行的函數(shù)放入map中，用map的key來作為實(shí)現(xiàn)順序，由于map取值是無序的，所以需要對(duì)用原子操作對(duì)goroutine加上自旋鎖，使其在沒有到達(dá)它的執(zhí)行順序時(shí)進(jìn)行等待。

package main

import (
    "fmt"
    "time"
    "sync/atomic"
)

type operation func(string)
func main(){
    var count uint32 = 1
    m := generate(&count,5,withPrint())
    //var i = uint32(0)、

      //由于map是無序取值，所有更能體現(xiàn)goroutine是順序執(zhí)行的
    for index,fn := range m{
        go fn(uint32(index))
    }
    time.Sleep(10*time.Second)
}

func withPrint()operation{
    return func(s string) {
        println(s)
    }
}

//創(chuàng)建map
func generate(cptr *uint32,total int,op operation)map[int]func(uint32){
    var m = make(map[int]func(order uint32),total)
    for i:=1;i<=total;i++ {
        m[i] = func(order uint32) {
            for  {
                              //比較order和count的值是否相等，不想等就自旋
                if !atomic.CompareAndSwapUint32(cptr,order,order){
                    time.Sleep(500*time.Millisecond)
                }else {
                    break
                }
            }
            s := fmt.Sprintf("this is goroutine %d",order)
            op(s)
            atomic.AddUint32(cptr,1)
        }
    }
    return m
}