written, werr, handled = poll.SendFile(&c.pfd, int(fd), remain)
		return true
	})
	if err == nil {
		err = werr
	}

	if lr != nil {
		lr.N = remain - written
	}
	return written, wrapSyscallError("sendfile", err), handled

			return 0, nil, true
		}
	}

	f, ok := r.(*os.File)
	if !ok {
		return 0, nil, false
	}

	written, err = poll.SendFile(&fd.pfd, syscall.Handle(f.Fd()), n)
	if err != nil {
		err = wrapSyscallError("transmitfile", err)
	}

	// If any byte was copied, regardless of any error
	// encountered mid-way, handled must be set to true.
	handled = written > 0

	return

		err = werr
	}

	if lr != nil {
		lr.N = remain - written
	}

	_, err1 := f.Seek(written, io.SeekCurrent)
	if err1 != nil && err == nil {
		return written, err1, handled
	}

	return written, wrapSyscallError("sendfile", err), handled