main processing loop, display graphs and maps

def main_loop():
    '''main processing loop, display graphs and maps'''
    while True:
        if mestate is None or mestate.exit:
            return
        while not mestate.input_queue.empty():
            line = mestate.input_queue.get()
            cmds = line.split(';')
            for c in cmds:
                process_stdin(c)
        time.sleep(0.1)