怀疑pyinotify存在线程问题

Question

我最近在使用pyinotify这个库，但遇到了一些问题。就是在对一个文件夹进行多次修改后，它就不再接收通知了。我觉得可能和有两个线程在运行有关，一个是通知线程，另一个是wxpython线程。

这个应用的目的是，当检测到IP连接时，加载一张图片到屏幕上，同时监控一个文件夹，查看里面是否有名为'Checklist'的文件，然后根据这个文件进行一些处理，比如移动文件。

这个程序偶尔能正常工作，但作为一个Python新手，我不太确定问题出在哪里，因为我基本上是拿着一个有线程的例子在改。有时候，它只收到一个通知，然后就不再接收文件变化的通知了。

另外，如果我重启Linux系统再试一次，它在接收了一段时间的文件变化通知后又会停止，这让我觉得可能是没有正确释放监控的设置？

如果有人能提供帮助，我会非常感激，同时也欢迎任何优化和改进的建议。我相信我能从反馈中学到很多东西。代码在下面

import pyinotify
import os.path
import shutil
import errno
import subprocess
import logging
import wx
import time
import signal
import sys

#update CHECKLIST name
CHECKLIST = 'Checklist' #this must exist in the update archive

#static values
DIR_UPDATE = 'd'
FILE_UPDATE = 'f'
PING_IP = ' localhost' # change in production

#paths
WATCH_PATH = '/home/test'
LOG_PATH = '/home/test/update.log'
CONNECTED_IMG = 'update.jpg'
UPDATING_IMG = 'updating.png'

#msgs
UPDATEFOUND_MSG = ' Update Found '
UPDATEUNZIPPEDSTART_MSG = ' Update unzipping '
UPDATEUNZIPPED_MSG = ' Update unzipped '
UPDATEFILE_MSG = ' Update file '
UPDATEFILEMSG_CONT = ' moved into path '
REMOVEFILEMSG_CONT = ' removed from update folder '
UPDATECOMPLETE_CONT = ' Update complete'
ROADANGELRESTART_MSG = ' Update restarting app '
DIRCREATED_MSG = ' Directory created at path '

#errors
UPDATEFAILED_MSG = ' Update process failed on '
BADLYFORMED_MSG = ' Badly formed src/dest combination '
UPDATESRCUNAVAILABLE = ' Invalid update file specified '
UPDATEDESTUNAVAILABLE = ' Invalid update destination specified '
INVALIDUPDATEFORMAT = ' Invalid format string '

#on startup create the watchfolder if it doesnt exist

WM = pyinotify.WatchManager() # Watch Manager
WM_MASK = pyinotify.IN_CLOSE_WRITE # watched events

#setup logger
LOGGER = logging.getLogger('Updater')
LOG_HANDLE = logging.FileHandler(LOG_PATH)
FORMATTER = logging.Formatter('%(asctime)s %(levelname)s %(message)s')
LOG_HANDLE.setFormatter(FORMATTER)
LOGGER.addHandler(LOG_HANDLE) 
LOGGER.setLevel(logging.INFO)


#Global values used primarily in the main function loop
HANDLER = None
NOTIFIER = None
WDD = None
UPDATE_UI = None
WINDOW = None
CURR_IMG = None
LAST_CURRIMG = None

class EventHandler(pyinotify.ProcessEvent):
    VERBOSE = False
    """ Main class to monitor file events and process accordingly"""

    def process_IN_CLOSE_WRITE(self, event):
        """ Only executes when a Checklist has finished being written to"""
        path = event.pathname
        print 'evt'
        #look for the update_ready file before processing
        if (os.path.basename(path) == 'Checklist'):
            EventHandler.parse_updates(WATCH_PATH)

            global CURR_IMG
            CURR_IMG = os.path.join(WATCH_PATH, UPDATING_IMG)
            show_window()
            print 'update completed'
            time.sleep(1000)

    @classmethod
    def parse_updates(cls, path):
        """ parses update files """
        #handle errors for opening the file
        file_path = os.path.join(path, CHECKLIST)
        print file_path

        files = open(file_path)
        #handle errors for malformed tuples-done
        #handle errors for unavailable files-done
        #handle errors for unavailable dests-done #created automatically
        #handle permission errors

        for line in files:
            #remove linebreaks etc and ensure its not empty
            if line.strip():
                array = line.split('=')
                length = len(array)
                if length == 3:
                    EventHandler.process_line(path, array)
                else:
                    if length > 0:
                        EventHandler.print_bad_msg(array[0])
                    else:
                        EventHandler.print_bad_msg()
        print 'removing ', file_path
        os.remove(file_path) #remove the checklist file

    @classmethod
    def mkdir(cls, path):
        """ makes a directory from a path"""
        try:
            os.mkdir(path)
            print DIRCREATED_MSG, path
        except OSError, err:
            print err
            if err.errno != errno.EEXIST: #thrown when the dir already exists
                return False

    @classmethod
    def move_file(cls, src, dest):
        """ moves a file from src to dest and remove after
            expects that the dest already exists at this point
            otherwise ignores the move"""
        #print 'moving from', src, 'to ', dest
        if os.path.isfile(dest):
            shutil.copy2(src, dest)
        else:
            print UPDATEDESTUNAVAILABLE
        #remove the src file when done
        os.remove(src)

    @classmethod
    def process_line(cls, path, array):
        """ process a line from the checklist"""
        #remove newlines etc
        update_file = array[0].strip()
        update_src = os.path.join(path, update_file)
        update_dest = array[1].strip()
        update_type = array[2].strip()

        #ensure we have valid values in all three fields
        if update_file and update_dest and update_type:
            #ensure the src file exists
            if os.path.isfile(update_src):
                #check if destination is directory and
                #copy the file into the directory

                if update_type == DIR_UPDATE:
                    EventHandler.mkdir(update_dest)
                    dest = os.path.join(update_dest, update_file)
                    EventHandler.move_file(update_src, dest)
                else:
                    EventHandler.move_file(update_src, update_dest)
            else:
                print UPDATESRCUNAVAILABLE

        else:
            print INVALIDUPDATEFORMAT


    @classmethod
    def print_bad_msg(cls, msg = ''):
        """ print a badly formed message with optional value"""
        if msg:
            print BADLYFORMED_MSG, msg
        else:
            print BADLYFORMED_MSG

class UpdateFrame(wx.Frame):
    """ Displays update images to screen"""
    def __init__(self, path):
        wx.Frame.__init__(self, None, wx.ID_ANY)

        image_file = path
        image = wx.Bitmap(image_file)
        image_size = image.GetSize()
        # set the frame size to fit the screen size
        self.SetClientSize(wx.DisplaySize())

        # bitmap's upper left corner is in frame position (x, y)
        # by default pos=(0, 0)
        wx.StaticBitmap(self, wx.ID_ANY, image, size = image_size)

        # the parent is the frame
        self.SetTitle('Update Mode')

def ping_ip():
    """ ping once to establish connection """
    ret = subprocess.call("ping -c 1 %s" % PING_IP,
            shell=True,
            stdout=open('/dev/null', 'w'),
            stderr=subprocess.STDOUT)
    if ret == 0:
        return True
    else:
        return False

def show_window():
    """ update screen window when currimage changes is set """ 
    global UPDATE_UI
    global WINDOW
    global CURR_IMG
    global LAST_CURRIMG

    if LAST_CURRIMG != CURR_IMG:
        if not UPDATE_UI:
            UPDATE_UI = wx.App()

        if not WINDOW:
            WINDOW = UpdateFrame(CURR_IMG)

        UPDATE_UI.ExitMainLoop()

        while(UPDATE_UI.IsMainLoopRunning()):
            pass

        WINDOW.Destroy()

        WINDOW = UpdateFrame(CURR_IMG)
        WINDOW.Show(True)

        UPDATE_UI.MainLoop()
        LAST_CURRIMG = CURR_IMG
        print 'changed'

def in_updatemode():
    return ping_ip()

while True:
    try:
        if not in_updatemode():
            print 'waiting for connect'
            time.sleep(3)

            if  NOTIFIER:
                NOTIFIER.stop()

        else:
            if not HANDLER:
                HANDLER = EventHandler()

            if not NOTIFIER:
                NOTIFIER = pyinotify.ThreadedNotifier(WM, HANDLER)
                NOTIFIER.start()

            if not WDD:
                WDD = WM.add_watch(WATCH_PATH, WM_MASK, rec=True,quiet=False)

            # ip is active so show the image and start the notifier
            # state = ip active 
            CURR_IMG = os.path.join(WATCH_PATH, CONNECTED_IMG)
            show_window()
            print 'here'
    except KeyboardInterrupt:
        print 'out'
        NOTIFIER.stop()
        break

多线程编程文件处理 linux系统 wxpython 文件监控 pyinotify 线程问题通知机制

怀疑pyinotify存在线程问题

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