sock.connect(monitor_path)
    except IOError as ex:
        if ex.errno == errno.ECONNREFUSED:
            # virtal machine is not running
            return None
        else:
            raise ex
    readfd, dummy_w, dummy_x = select.select([sock], [], [], 0.001)
    readfd, dummy_w, dummy_x = select.select([sock], [], [], 0.1)
    if sock in readfd:
        dummy_greeting = sock.recv(1024)
    return sock

def send_command(sock, command):
    """ Sends monitor command to given socket and returns answer """
    fcntl.flock(sock, fcntl.LOCK_EX)