Is data conflict between MIDIIN thread and main function loop?

[Hi-Music]

Thank you，SpotlightKid！Python-rtmidi is the best Python binding for RtMidi in the world! I am reading the midiclock.py in examples\advanced. I find that clock (MIDIClockReceiver instance) is shared between MIDIIN thread and main function loop. Can you tell me that Is there data conflict between MIDIIN thread and main function loop? I think that main loop and midiin should not write or read clock at the same time. Thank you very much!

def main(args=None):
    ap = argparse.ArgumentParser(usage=__doc__.splitlines()[0])
    ap.add_argument('-p', '--port', help="MIDI input port index / name.")
    ap.add_argument('bpm', type=int, default=120, help="Starting BPM.")
    args = ap.parse_args(args)
    clock = MIDIClockReceiver(args.bpm)
    try:
        m_in, port_name = open_midiinput(args.port)
    except (EOFError, KeyboardInterrupt):
        return 1
    
    #clock is shared between MIDIIN thread and main function loop.
    m_in.set_callback(clock)
    # Important: enable reception of MIDI Clock messages (status 0xF8)
    m_in.ignore_types(timing=False)

    try:
        print("Waiting for clock sync...")
        while True:
            time.sleep(1)

            if clock.running:
                if clock.sync:
                    print("%.2f bpm" % clock.bpm)
                else:
                    print("%.2f bpm (no sync)" % clock.bpm)

    except KeyboardInterrupt:
        pass
    finally:
        m_in.close_port()
        del m_in