code: func (do *Domain) LoadBindInfoLoop(ctx sessionctx.Context) error {
  	ctx.GetSessionVars().InRestrictedSQL = true
  	do.bindHandle = bindinfo.NewBindHandle(ctx)
  	err := do.bindHandle.Update(true)
  	if err != nil {
  		return err
  	}
  
  	do.loadBindInfoLoop()
  	do.handleInvalidBindTaskLoop()
  	return nil
  }
docs: // LoadBindInfoLoop create a goroutine loads BindInfo in a loop, it should
  // be called only once in BootstrapSession.