Logger does not work with python multiprocessing

我在寫一個測試程序，使用python multiprocessing。我正在使用記錄器記錄所取得的進展。然而，記錄器似乎不起作用。它不會從子進程內記錄或打印。不清楚發生了什麼問題。用普通打印語句替換記錄器也無濟於事。下面是我的代碼：Logger does not work with python multiprocessing

from multiprocessing import Pool 
from multiprocessing.pool import ApplyResult 
import time 
import os 
import logging 
import multiprocessing 
import sys 

logger=[] 
class C(object): 

    def __init__(self, a, b=1): 
     self.a = a 
     self.b = b   


    def f(self, name): 
     global logger 
     time.sleep(2) 
     logger.info('****Inside f..******') 
     return str(os.getpid())     


    def call_back(self, x): 
     print 'Inside callback', x 



    def _run(self): 
     print 'Reached inside run..' 
     print 'main process id ..', os.getpid() 
     pool = Pool(processes=6) 
     names = ['frank', 'justin', 'osi', 'thomas', 'jim', 'rock', 'stonecold', 'machoman']   
     result = pool.map_async(unwrap_self_f, zip([self]*len(names), names), 1, callback=self.call_back) 
     result.wait() 
     print type(result) 
     print result 


    def hello(self): 
     print 'Running hello....' 
     self._run() 

def test(): 
    logger.info('Starting....test') 
    c = C(1, 2) 
    print 'Running test....' 
    c.hello()  

def unwrap_self_f(arg, **kwarg): 
    print 'inside unwrap_self_f' 
    return C.f(*arg, **kwarg)  

if __name__ == '__main__': 
    print 'Loading multiprocessing...' 
    logger = multiprocessing.log_to_stderr() 
    logger.setLevel(logging.DEBUG) 
    test()

，我得到的輸出如下：

Loading multiprocessing... 
[INFO/MainProcess] Starting....test 
Running test.... 
Running hello.... 
Reached inside run.. 
main process id .. 19056 
[DEBUG/MainProcess] created semlock with handle 520 
[DEBUG/MainProcess] created semlock with handle 532 
<class 'multiprocessing.pool.MapResult'> 
<multiprocessing.pool.MapResult object at 0x030FFB30> 
[DEBUG/MainProcess] finalizing pool 
[DEBUG/MainProcess] helping task handler/workers to finish 
[DEBUG/MainProcess] task handler got sentinel 
[DEBUG/MainProcess] removing tasks from inqueue until task handler finished 
[DEBUG/MainProcess] task handler sending sentinel to result handler 
[DEBUG/MainProcess] task handler sending sentinel to workers 
[DEBUG/MainProcess] result handler got sentinel 
[DEBUG/MainProcess] task handler exiting 
[DEBUG/MainProcess] terminating workers 
[DEBUG/MainProcess] ensuring that outqueue is not full 
[DEBUG/MainProcess] joining task handler 
[DEBUG/MainProcess] result handler exiting: len(cache)=0, thread._state=2 
[DEBUG/MainProcess] joining result handler 
[DEBUG/MainProcess] joining pool workers

它不記錄「 '****裏面˚F.. ******' 「（從函數f）請任何人都可以幫我弄清楚我做錯了什麼。用多記錄似乎一個難啃:( 我使用Python 2.6.6 OS是Windows的32位/ 64位。

來源

2014-12-02 LearnToLive

衍生的進程將不會有他們的記錄初始化。所以，你需要調用multiprocessing.log_to_stderr在每個過程中的代碼（如unwrap_self_f）以及主過程中將被訪問的地方。例如：

def unwrap_self_f(arg, **kwarg): 
    global logger 
    print 'inside unwrap_self_f' 
    logger = multiprocessing.log_to_stderr() 
    logger.setLevel(logging.DEBUG) 
    return C.f(*arg, **kwarg)

來源

2014-12-03 10:33:35

Logger does not work with python multiprocessing

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