[Tutor] unexpected signal behaviour

Alan Gauld alan.gauld at btinternet.com
Sun Nov 25 10:59:44 CET 2007


I can't see anything obvious.

Try putting some debug messages into read_config
and the main loop.

Also you could try catching the SystemExit exception at
the top level and dumping a stacktrace to see exactly
where it is exiting.

HTH,

Alan G.


"dave selby" <dave6502 at googlemail.com> wrote in message 
news:f52017b60711240549u69120675sd428eee8a83e1a6b at mail.gmail.com...
> Hi all,
>
> I have written a daemon as part of a larger project, if it recieves 
> a
> SIGHUP signal it needs to re-read its config file. It works in that 
> I
> get 'signal HUP detected, re-reading config file' in syslog but then
> the script exits ... mmm .... first time I have used signal catching
> ... thought it would continue its infinate loop. Any idea anyone ?
>
> Cheers
>
> Dave
>
>
>
>
> import os,  sys, time, signal, ConfigParser, kmotion_logger
>
> class Kmotion_Hkd2:
>
>    def __init__(self):
>        self.snap_init = [ 0 for i in xrange(16) ]
>        self.snap_count = [ 0 for i in xrange(16) ]
>        self.video_dir = ''
>        self.motion_feeds = ''
>        self.logger = kmotion_logger.Logger('kmotion_hdk2', 'DEBUG')
>        signal.signal(signal.SIGHUP, self.signal_hup)
>        self.read_config()
>
>    def start_daemon(self):
>        self.logger.log('daemon starting ...', 'DEBUG')
>        """" Start the house keeping 2 daemon """
>        while(True):
>            target_date = time.strftime('%Y%m%d')
>            # Scan the feeds
>            for feed in xrange(self.motion_feeds):
>                target_tmp = '%s/%s/%02i/tmp/' % (self.video_dir,
> target_date, (feed + 1))
>                target_video = '%s/%s/%02i/video/' % (self.video_dir,
> target_date, (feed + 1))
>
>                # If target_date or target_tmp don't exist they will
> shortly as motion auto generates them
>                # If target_video doesn't exist, could be just no
> motion so add dir
>                if not(os.path.isdir(self.video_dir + '/' +
> target_date)) or not(os.path.isdir(target_tmp)): continue
>                if not(os.path.isdir(target_video)): 
> os.mkdir(target_video)
>
>                jpeg_list = os.listdir(target_tmp)
>                jpeg_list.sort()
>
>                while (len(jpeg_list) >= 3):
>                    jpeg = jpeg_list[:1][0]
>                    self.snap_count[feed] = self.snap_count[feed] - 1
>
>                    if  self.snap_count[feed]:
>                        # Still counting down the snap_count[], so
> delete the snapshot
>                        self.logger.log('deleteing snapshot %s' %
> (target_tmp + jpeg), 'DEBUG')
>                        os.remove(target_tmp + jpeg)
>
>                    else:  # snap_count[] = 0, reset it & do 
> something
> with the snapshot
>                        self.snap_count[feed] = self.snap_init[feed]
>
>                        if os.path.isdir(target_video + jpeg[:-4]) or
> not(self.snap_init[feed]):
>                            # If there is a video file dir or if
> snap_init[feed] = 0, we dont need a snapshot so remove it
>                            self.logger.log('remove snapshot due to
> video clash %s/tmp/%s' % (self.video_dir, jpeg), 'DEBUG')
>                            os.remove(target_tmp + jpeg)
>
>                        else:  # No video file dir, move the snapshot
>                            self.logger.log('rename %s %s' %
> (target_tmp + jpeg, target_video + jpeg), 'DEBUG')
>                            os.rename(target_tmp + jpeg, target_video 
> + jpeg)
>
>                    jpeg_list = jpeg_list[1:]
>            time.sleep(2)
>
>    def read_config(self):
>        """ Read config file from 
> '~/.kde/share/apps/kmotion/kmotion.rc' """
>        parser = ConfigParser.SafeConfigParser()
>        parsed =
> parser.read(os.path.expanduser('~/.kde/share/apps/kmotion/kmotion.rc'))
>        if parsed[0][-10:] != 'kmotion.rc':
>            emsg = 'Can\'t open config file %s - killing motion & all
> daemon processes' % (parsed[0][-10:])
>            self.logger.log(emsg, 'CRIT')
>            self.kill_daemons()
>            sys.exit()
>
>        try:
>            self.video_dir = parser.get('misc', 'video_dir')
>            self.motion_feeds = 0  # Get ready to count the live 
> feeds
>            for i in xrange(0, 16):
>                self.snap_init[i] = int(parser.get('feed%s' %
> (str(i)), 'snapshot_interval'))
>                if parser.get('feed%s' % (str(i)), 'live') == "yes" :
> self.motion_feeds = self.motion_feeds + 1
>        except:
>            emsg = 'Corrupt config %s - Killing motion & all daemons
> processes' %  (sys.exc_info()[1])
>            self.logger.log(emsg, 'CRIT')
>            self.kill_daemons()
>            sys.exit()
>
>        for i in xrange(16):  # Force an immediate snapshot on all 
> feeds
>            self.snap_count[i] = 1
>
>    def kill_daemons(self):
>        """ Kill motion & all daemons """
>        os.system('killall -q motion')
>        os.system('pkill -f \'python.+kmotion_hkd1.py\'')
>
>    def signal_hup(self, signum, frame):
>            """ Re-read the config file on SIGHUP """
>            self.logger.log('signal HUP detected, re-reading config
> file', 'DEBUG')
>            self.read_config()
>
> if __name__ == '__main__':
>    Hkd2 = Kmotion_Hkd2()
>    Hkd2.start_daemon()
>
>
>
> -- 
>
> Please avoid sending me Word or PowerPoint attachments.
> See http://www.gnu.org/philosophy/no-word-attachments.html
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
> 




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