Logging thread with Queue and multiple threads to log messages

[scriptlearner at gmail.com]

I am trying to put up a queue (through a logging thread) so that all
worker threads can ask it to log messages.  However, the problem I am
facing is that, well, the logging thread itself is running forever.
It does not know when it should exit.  Any suggestion?  None of the
worker threads knows for sure when the logging thread should exit
since they don't know what other worker threads are doing.  I also try
to set a time limit for the logging thread, but it does not work.


# mylogging.py - used by everyone else that needs to log messages
import threading
import Queue
import time

# This is the queue object that's used to hold log events.
# LoggingThread knows about it, and the log() function below
# knows about it.  No one else is allowed to see it.
_log_queue = Queue.Queue()

class LoggingThread(threading.Thread):
    def __init__(self,logfile,duration):
        threading.Thread.__init__(self)
        self.logfile = logfile
        self.duration = duration

    def run(self):
        f=open(self.logfile, 'w')
        #it's probably not the right way to set an end time here
        #since the logging thread should wait until all worker threads
are done
        end = time.time() + self.duration + 10
        while(end > time.time()):
            message = _log_queue.get()
            f.write(message + '\n')  # (or whatever)

        f.close()

# Kick off the logging thread.
LoggingThread("logs/myapp.log",20).start()

def log(msg):
    _log_queue.put(msg)




class Worker(threading.Thread):
    def __init__(self,no,duration):
        threading.Thread.__init__(self)
        self.no = no
        self.duration = duration

    def run(self):
        end = time.time() + self.duration

        while(end > time.time()):
            log('Thread Object (%d):(%d), Time:%s in seconds %d'%
(self.no,self.duration,time.ctime(),time.time()))
            time.sleep(10)

        print 'Done with worker (%d) at %s'%(self.no,time.ctime())



def main():
    children = []
    args = parseArgs()

    for i in range(args.threads):
        log('i=%d'%(i))
        children.append(Worker(i,args.duration))
        children[i].start()
        time.sleep(0.1)