c.Control(func(fdPtr uintptr) {
			// got socket file descriptor to set parameters.
			fd := int(fdPtr)

			_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)

			_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)

			// Enable custom socket send/recv buffers.
			if opts.SendBufSize > 0 {
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF, opts.SendBufSize)
			}

			if opts.RecvBufSize > 0 {

  @Test
  fun testFileDescriptor() {
    assertOnFileDescriptor { fd ->
      val requestBody = fd.toRequestBody()

      assertThat(requestBody.contentLength()).isEqualTo(-1L)
      assertThat(requestBody.isOneShot()).isEqualTo(true)
    }
  }

  @Test
  fun testFileDescriptorRead() {
    assertOnFileDescriptor(content = "Hello") { fd ->
      val requestBody = fd.toRequestBody()

      val buffer = Buffer()

	}
	return nil
}

// openFileWithFD return 'fd' based file descriptor
func openFileWithFD(name string, flag int, perm os.FileMode) (fd int, err error) {
	switch flag & writeMode {
	case writeMode:
		defer updateOSMetrics(osMetricOpenFileWFd, name)(err)
	default:
		defer updateOSMetrics(osMetricOpenFileRFd, name)(err)
	}
	var e error
	fd, e = syscall.Open(name, flag|syscall.O_CLOEXEC, uint32(perm))
	if e != nil {

	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.
func DisableDirectIO(f *os.File) error {
	fd := f.Fd()
	flag, err := unix.FcntlInt(fd, unix.F_GETFL, 0)
	if err != nil {
		return err
	}
	flag &= ^(syscall.O_DIRECT)
	_, err = unix.FcntlInt(fd, unix.F_SETFL, flag)
	return err
}

// AlignedBlock - pass through to directio implementation.
func AlignedBlock(blockSize int) []byte {

	fd, err := syscall.CreateFile(pathp, access, shareflag, nil, createflag, accessAttr, 0)
	if err != nil {
		return nil, err
	}

	return os.NewFile(uintptr(fd), path), nil
}

func lockFile(fd syscall.Handle, flags uint32) error {
	// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx
	if fd == syscall.InvalidHandle {
		return nil
	}

					return;
				}
				const n = this.writeSync(fd, buf);
				callback(null, n);
			},
			chmod(path, mode, callback) { callback(enosys()); },
			chown(path, uid, gid, callback) { callback(enosys()); },
			close(fd, callback) { callback(enosys()); },
			fchmod(fd, mode, callback) { callback(enosys()); },
			fchown(fd, uid, gid, callback) { callback(enosys()); },
			fstat(fd, callback) { callback(enosys()); },

	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.
func DisableDirectIO(f *os.File) error {
	fd := f.Fd()
	_, err := unix.FcntlInt(fd, unix.F_NOCACHE, 0)
	return err
}

// AlignedBlock - pass through to directio implementation.
func AlignedBlock(blockSize int) []byte {
	return directio.AlignedBlock(blockSize)

	}
}

// NewLexer returns a lexer for the named file and the given link context.
func NewLexer(name string) TokenReader {
	input := NewInput(name)
	fd, err := os.Open(name)
	if err != nil {
		log.Fatalf("%s\n", err)
	}
	input.Push(NewTokenizer(name, fd, fd))
	return input
}

// The other files in this directory each contain an implementation of TokenReader.

	}
	in.expectNewline("#include")
	// Push tokenizer for file onto stack.
	fd, err := os.Open(name)
	if err != nil {
		for _, dir := range in.includes {
			fd, err = os.Open(filepath.Join(dir, name))
			if err == nil {
				break
			}
		}
		if err != nil {
			in.Error("#include:", err)
		}
	}
	in.Push(NewTokenizer(name, fd, fd))
}

// #line processing.
func (in *Input) line() {

			fdMu.Lock()
			defer fdMu.Unlock()
			if len(fds) == 0 {
				return nil
			}
			fdsCopy := fds
			for _, fd := range fdsCopy {
				// Grab a fallback disk
				fds = fds[1:]
				if fd != nil && fd.IsOnline() {
					return fd
				}
			}
		}
		// Either no more disks for fallback or
		// not a storage error.
		return nil
	}