Flush properly log file on Ctrl+C termination

[m3d]

This bug made me crazy for "years" :( ... if you kill some recording with Ctrl+C where there are not many data typically everything was lost (only 16 bytes header was available). This solves the problem (tested with LoRa base-station logger).

[tajgr]

It is working but i tested it on systemmonitor driver and there is a bug in dmesg parsing. I got:

python -m osgar.record config/test-system-monitor.json 
2025-08-22 10:57:50,052 __main__         INFO     /home/jakub/git/logs_osgar/test-system-monitor-250822_085750.log
2025-08-22 10:57:50,064 __main__         INFO     SIGINT handler installed
dmesg: čtení z jaderného bufferu selhalo: Operace není povolena
Exception in thread Thread-1 (run_input):
Traceback (most recent call last):
  File "/home/jakub/miniconda3/envs/osgar/lib/python3.10/threading.py", line 1009, in _bootstrap_inner
    self.run()
  File "/home/jakub/miniconda3/envs/osgar/lib/python3.10/threading.py", line 946, in run
    self._target(*self._args, **self._kwargs)
  File "/home/jakub/git/osgar/osgar/drivers/system_monitor.py", line 91, in run_input
    dmesg = self.process_dmesg(dmesg_all)
  File "/home/jakub/git/osgar/osgar/drivers/system_monitor.py", line 43, in process_dmesg
    dmesg_time = self.find_last_dmesg_time(dmesg_all)
  File "/home/jakub/git/osgar/osgar/drivers/system_monitor.py", line 34, in find_last_dmesg_time
    dmesg_time = get_timestamp_from_dmesg(dmesg_all[ii])
IndexError: list index out of range
Traceback (most recent call last):
  File "/home/jakub/miniconda3/envs/osgar/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/home/jakub/miniconda3/envs/osgar/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/home/jakub/git/osgar/osgar/record.py", line 106, in <module>
    main()
  File "/home/jakub/git/osgar/osgar/record.py", line 102, in main
    record(cfg, log_prefix=prefix, duration_sec=args.duration, log_filename=args.log)
  File "/home/jakub/git/osgar/osgar/record.py", line 68, in record
    with LogWriter(prefix=log_prefix, filename=log_filename, note=str(sys.argv)) as log:
  File "/home/jakub/git/osgar/osgar/logger.py", line 158, in __exit__
    self.close()
  File "/home/jakub/git/osgar/osgar/logger.py", line 149, in close
    self.f.close()
AttributeError: 'NoneType' object has no attribute 'close'

The logger was probably already closed. So, add a check that logger is not None?

[m3d]

OK, thanks for test. I can confirm that if I use duration if crashes (with Ctrl+C it is OK). Your case seems to be related to sudo??

(osgar) md@md-ThinkPad-P50:~/git/osgar$ python -m osgar.record config/test-system-monitor.json --duration 10
2025-08-22 20:25:11,327 root             WARNING  Environment variable OSGAR_LOGS is not set - using working directory
2025-08-22 20:25:11,328 __main__         INFO     /home/md/git/osgar/test-system-monitor-250822_182511.log
2025-08-22 20:25:11,339 __main__         INFO     SIGINT handler installed
Traceback (most recent call last):
  File "/usr/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/home/md/git/osgar/osgar/record.py", line 106, in <module>
    main()
  File "/home/md/git/osgar/osgar/record.py", line 102, in main
    record(cfg, log_prefix=prefix, duration_sec=args.duration, log_filename=args.log)
  File "/home/md/git/osgar/osgar/record.py", line 77, in record
    recorder.request_stop()
  File "/home/md/git/osgar/osgar/logger.py", line 158, in __exit__
    self.close()
  File "/home/md/git/osgar/osgar/logger.py", line 149, in close
    self.f.close()
AttributeError: 'NoneType' object has no attribute 'close'

[m3d]

well, I do not like this hack with multiple calls of close(), but ... if you have any suggestion, please let me know

[tajgr]

Maybe add to LogWriter some variable, e.g. log_closed and than check whereas it is ture. But current solution is working.

[m3d]

well, log_closed is identical to file descriptor to be None, or not?

[tajgr]

Yes, actually. You can ask if the file is None or not..

[m3d]

well, this is the place where I ask, or maybe I do not understand? (note, that logger is shared among multiple modules)

[tajgr]

The idea was move the if to the record. It could be maybe clearer.. but you can ignore it.

[m3d]

OK, thanks