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mplog: Python advanced multiprocessing logging.
import logging
import multiprocessing
import time
import mplog
FORMAT = '%(asctime)s - %(processName)s - %(levelname)s - %(message)s'
logging.basicConfig(level=logging.DEBUG, format=FORMAT)
existing_logger = logging.getLogger('x')
def subprocess(n):
existing_logger.info('y')
logger = logging.getLogger('sub')
logger.info('Before sleep.')
time.sleep(0.01)
logger.info('After sleep.')
root = logging.getLogger()
root.debug('Root log message.')
def start_processes(log_queue):
procs = list()
for i in xrange(5):
proc = multiprocessing.Process(target=mplog.logged_call,
args=(log_queue, subprocess, i))
proc.start()
procs.append(proc)
for proc in procs:
proc.join()
def main():
existing_logger.info('Before')
with mplog.open_queue() as log_queue:
existing_logger.info('In context manager.')
start_processes(log_queue)
existing_logger.info('At the end.')
logging.info('Now really quitting.')
if __name__ == '__main__':
main()
'''
MIT License
Copyright (c) 2019, Marc Schlaich.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
'''
import contextlib
import multiprocessing
import logging
import threading
def daemon(log_queue):
while True:
try:
record_data = log_queue.get()
if record_data is None:
break
record = logging.makeLogRecord(record_data)
logger = logging.getLogger(record.name)
if logger.isEnabledFor(record.levelno):
logger.handle(record)
except (KeyboardInterrupt, SystemExit):
raise
except EOFError:
break
except:
logging.exception('Error in log handler.')
class MPLogger(logging.Logger):
log_queue = None
def isEnabledFor(self, level):
return True
def handle(self, record):
ei = record.exc_info
if ei:
# to get traceback text into record.exc_text
logging._defaultFormatter.format(record)
record.exc_info = None # not needed any more
d = dict(record.__dict__)
d['msg'] = record.getMessage()
d['args'] = None
self.log_queue.put(d)
def logged_call(log_queue, func, *args, **kwargs):
MPLogger.log_queue = log_queue
logging.setLoggerClass(MPLogger)
# monkey patch root logger and already defined loggers
logging.root.__class__ = MPLogger
for logger in logging.Logger.manager.loggerDict.values():
if not isinstance(logger, logging.PlaceHolder):
logger.__class__ = MPLogger
func(*args, **kwargs)
@contextlib.contextmanager
def open_queue():
log_queue = multiprocessing.Queue()
daemon_thread = threading.Thread(target=daemon, args=(log_queue,))
daemon_thread.start()
yield log_queue
log_queue.put(None)
$ python example.py
2013-10-16 09:27:16,526 - MainProcess - INFO - Before
2013-10-16 09:27:16,545 - MainProcess - INFO - In context manager.
2013-10-16 09:27:16,634 - Process-1 - INFO - y
2013-10-16 09:27:16,634 - Process-1 - INFO - Before sleep.
2013-10-16 09:27:16,637 - Process-2 - INFO - y
2013-10-16 09:27:16,638 - Process-2 - INFO - Before sleep.
2013-10-16 09:27:16,644 - Process-1 - INFO - After sleep.
2013-10-16 09:27:16,644 - Process-1 - DEBUG - Root log message.
2013-10-16 09:27:16,645 - Process-3 - INFO - y
2013-10-16 09:27:16,645 - Process-3 - INFO - Before sleep.
2013-10-16 09:27:16,648 - Process-2 - INFO - After sleep.
2013-10-16 09:27:16,648 - Process-2 - DEBUG - Root log message.
2013-10-16 09:27:16,651 - Process-4 - INFO - y
2013-10-16 09:27:16,651 - Process-4 - INFO - Before sleep.
2013-10-16 09:27:16,655 - Process-3 - INFO - After sleep.
2013-10-16 09:27:16,655 - Process-3 - DEBUG - Root log message.
2013-10-16 09:27:16,661 - Process-4 - INFO - After sleep.
2013-10-16 09:27:16,661 - Process-4 - DEBUG - Root log message.
2013-10-16 09:27:16,684 - Process-5 - INFO - y
2013-10-16 09:27:16,684 - Process-5 - INFO - Before sleep.
2013-10-16 09:27:16,694 - Process-5 - INFO - After sleep.
2013-10-16 09:27:16,694 - Process-5 - DEBUG - Root log message.
2013-10-16 09:27:16,697 - MainProcess - INFO - At the end.
2013-10-16 09:27:16,697 - MainProcess - INFO - Now really quitting.
@anka-213

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commented Aug 3, 2015

What is the licence of this code? May I use this for an commercial closed-source project?

@anka-213

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commented Aug 3, 2015

It looks awesome by the way.

@JohnMaguire

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commented Jan 8, 2016

@schlamar Thanks for this! Also curious what license it's under.

If you ever setup a dedicated repository for this, please let me know. 👍

@jenner-luo

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commented Jul 7, 2017

awesome

@MartyMacGyver

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commented Jul 10, 2017

FYI, commenting on a gist won't notify the author (isaacs/github#21)

That said, this is pretty cool - seems to work on Python 3.6 if you change the xrange() call to just range()

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Owner Author

commented Mar 9, 2019

Added MIT License

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