Go - 并发

package main
import (
   "fmt"
   "time"
   "sync"
)
var wg = sync.WaitGroup{}

func main() {
   wg.Add(2)
   go fun1()
   go fun2()
   wg.Wait()
}
func fun1(){
   for  i:=0;i<10;i++{
      fmt.Println("fun1,  ->",i)
      time.Sleep(time.Duration(5*time.Millisecond))
   }
   wg.Done()
}
func fun2(){
   for i:=0;i<10;i++{
      fmt.Println("fun2,  ->",i)
      time.Sleep(time.Duration(10*time.Millisecond))
   }
   wg.Done()
}