ex.go

func GodDoSomething(ctx Contex){
  c := make(chan struct{})
  go func() {
        defer close(c)
        wg.Wait()
  }()
  
  ds1ctx ,ds1CancelFunc := context.WithCancel(ctx)
  wg.Add(1)
  go DoSomething1(ds1ctx, wg)
  
  ds2ctx ,ds2CancelFunc := context.WithCancel(ctx)
  wg.Add(1)
  go DoSomething2(ds2ctx, wg)
  
  select {
  case <-c:
    // Complete normally
    return
  case ctx.Done():
    // Cancel by who call you
    ds1CancelFunc()
    ds2CancelFunc()
    return
  }
}