go sync.WaitGroup

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

var a int64 = 0
var b int64 = 0

func main() {
   wg:=sync.WaitGroup{}
   wg.Add(1)
   go func() {
      defer wg.Done()
      a=1
      b=2

   }()

   wg.Wait()

    go func() {
     fmt.Println(a,b)
  }()
   time.Sleep(time.Millisecond)

}

//
1 2