func lockFileEx(h syscall.Handle, flags, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
	reserved := uint32(0)
	r1, _, e1 := syscall.Syscall6(procLockFileEx.Addr(), 6, uintptr(h), uintptr(flags),
		uintptr(reserved), uintptr(locklow), uintptr(lockhigh), uintptr(unsafe.Pointer(ol)))
	if r1 == 0 {
		if e1 != 0 {
			err = error(e1)
		} else {
			err = syscall.EINVAL
		}
	}
	return

	//   _Out_ LPDWORD lpTotalNumberOfClusters
	// );
	_, _, _ = GetDiskFreeSpace.Call(uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(path))),
		uintptr(unsafe.Pointer(&lpSectorsPerCluster)),
		uintptr(unsafe.Pointer(&lpBytesPerSector)),
		uintptr(unsafe.Pointer(&lpNumberOfFreeClusters)),
		uintptr(unsafe.Pointer(&lpTotalNumberOfClusters)))

	info.Files = uint64(lpTotalNumberOfClusters)

	// golang.org/issue/15653
	dirent := (*syscall.Dirent)(unsafe.Pointer(&buf[0]))
	if v := unsafe.Offsetof(dirent.Reclen) + unsafe.Sizeof(dirent.Reclen); uintptr(len(buf)) < v {
		return consumed, nil, typ, fmt.Errorf("buf size of %d smaller than dirent header size %d", len(buf), v)
	}
	if len(buf) < int(dirent.Reclen) {

	"golang.org/x/sys/unix"
)

func setTCPParametersFn(opts TCPOptions) func(network, address string, c syscall.RawConn) error {
	return func(network, address string, c syscall.RawConn) error {
		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)

					} else {
						var resultErrno, expectErrno uintptr
						if pathErr, ok := err.(*os.PathError); ok {
							if errno, pok := pathErr.Err.(syscall.Errno); pok {
								resultErrno = uintptr(errno)
							}
						}
						if pathErr, ok := testCase.expectedErr.(*os.PathError); ok {
							if errno, pok := pathErr.Err.(syscall.Errno); pok {
								expectErrno = uintptr(errno)
							}
						}