return nil, fmt.Errorf("missing option must be provided")
		}
		return nil, fmt.Errorf("provided option cannot be empty")
	}

	// Disallow relative paths, figure out absolute paths.
	dirAbs, err := filepath.Abs(dir)
	if err != nil {
		return nil, err
	}
	err = mkdirAllIgnorePerm(dirAbs)
	if err != nil {
		return nil, fmt.Errorf("unable to create the directory `%s`: %w", dirAbs, err)
	}

var globalLoggerOutput io.WriteCloser

func initializeLogRotate(ctx *cli.Context) (io.WriteCloser, error) {
	lgDir := ctx.String("log-dir")
	if lgDir == "" {
		return os.Stderr, nil
	}
	lgDirAbs, err := filepath.Abs(lgDir)
	if err != nil {
		return nil, err
	}
	lgSize := ctx.Int("log-size")
	output, err := logger.NewDir(logger.Options{
		Directory:       lgDirAbs,
		MaximumFileSize: int64(lgSize),

// Parameters are the same as in the constructor.
func (d *dynamicSleeper) Update(factor float64, maxWait time.Duration) error {
	d.mu.Lock()
	defer d.mu.Unlock()
	if math.Abs(d.factor-factor) < 1e-10 && d.maxSleep == maxWait {
		return nil
	}
	// Update values and cycle waiting.
	xioutil.SafeClose(d.cycle)
	d.factor = factor
	d.maxSleep = maxWait
	d.cycle = make(chan struct{})

}

func getValidPath(path string) (string, error) {
	if path == "" {
		return path, errInvalidArgument
	}

	var err error
	// Disallow relative paths, figure out absolute paths.
	path, err = filepath.Abs(path)
	if err != nil {
		return path, err
	}

	fi, err := Lstat(path)
	if err != nil && !osIsNotExist(err) {
		return path, err
	}
	if osIsNotExist(err) {
		// Disk not found create it.

little fidelity for improved speed. One can revert to the old behavior by
specifying the attribute `dct_method='INTEGER_ACCURATE'`. * `tf.complex_abs` has
been removed from the Python interface. `tf.abs` supports complex tensors and
should be used instead. * In the C++ API (in tensorflow/cc), Input, Output, etc.
have moved from the tensorflow::ops namespace to tensorflow. *