An event stream from Supervisor.

def supervisor_events(stdin, stdout):
    """
    An event stream from Supervisor.
    """

    while True:
        stdout.write('READY\n')
        stdout.flush()

        line = stdin.readline()
        headers = get_headers(line)

        payload = stdin.read(int(headers['len']))
        event_headers, event_data = eventdata(payload)

        yield event_headers, event_data

        stdout.write('RESULT 2\nOK')
        stdout.flush()