Method doUpgrade

upgrader.go:247–277

()

}

func (u *Upgrader) doUpgrade() (*os.File, error) {
	child, err := startChild(u.env, u.Fds.copy())
	if err != nil {
		return nil, fmt.Errorf("can't start child: %s", err)
	}

	readyTimeout := time.After(u.opts.UpgradeTimeout)
	for {
		select {
		case request := <-u.upgradeC:
			request <- errors.New("upgrade in progress")

		case err := <-child.result:
			if err == nil {
				return nil, fmt.Errorf("child %s exited", child)
			}
			return nil, fmt.Errorf("child %s exited: %s", child, err)

		case <-u.stopC:
			child.Kill()
			return nil, errors.New("terminating")

		case <-readyTimeout:
			child.Kill()
			return nil, fmt.Errorf("new child %s timed out", child)

		case file := <-child.ready:
			return file, nil
		}
	}
}

// This file must never be closed by the Go runtime, since its used by the
// child to determine when the parent has died. It must only be closed