Python Threading

[jesuisbenjamin]

Hello there,

i am working on an applet for Cairo-Dock (working with the provided API). The applet must perform a repetitive task every minute while being available for callbacks. So i looked into threading for python and found this nice tutorial (http://en.wikibooks.org/wiki/Python_Programming/Threading).
Now my applet is OO programming. This means the thread (which should count down before running processes of the applet) should be initialised from a process of the applet. I tried that and made the function to be run as a thread a process of applet, or a global function or another object, but in each case it failed.
I think i am doing something wrong, can anyone guide me?

To sum up:


The applet should run and perform some tasks
A loop should start (say every minute)
Meanwhile the applet should be able to perform some more tasks
When the loop ends the applet should perform special tasks and the loop should start again.
... and so on ect.


Thanks
Benjamin

[wmcbrine]

Post your code...

[jesuisbenjamin]

[Full Edit: Found better code, but not perfect]

I made some test first, using threading.Timer() and it worked fine:


#!/usr/bin/python

import time
import threading

def timer(sometime, obj):
print "...beginning timer"
t = threading.Timer(sometime, timer, [sometime, obj])
t.start()
obj.poke()

class thing(object):
def __init__(self):
self.time = 5

def run_timer(self):
timer(self.time, self)

def poke(self):
print "ouch!"

if __name__ == '__main__':
o = thing()
o.run_timer()

But when i apply that to my Applet the threading.Timer() seems to run only once... :(


#!/usr/bin/python

# This is a part of the external applets for Cairo-Dock
# Copyright : (C) 2011 by Benjamin
# E-mail : jesuisbenjamin@...
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# http://www.gnu.org/licenses/licenses.html#GPL
#
# This program depends on fbcmd, a command line interface (CLI) for facebook.
# http://fbcmd.dtompkins.com/

####################
### dependancies ###
####################

from CDApplet import CDApplet
import os
import threading
import time

####################
### Thread Class ###
####################

def countdown(sometime, app):
print "...countdown started"
t = threading.Timer(sometime, countdown, [sometime, app])
t.start()
app.read_fb()

####################
### Applet class ###
####################
class Applet(CDApplet):
def __init__(self):
# define internal variables:
# counter to display
self.counter = 1
# data retrieved from faceBook with fbcmd
self.fb = {}
# timer before refreshing data
self.timer = 1
# call high-level init
CDApplet.__init__(self)

##### private methods #####
def read_fb(self):
print "...reading data from faceBook"
# run the "fbcmd NOTIFY" command and return and parse result in "fblist" list
fblist = os.popen("fbcmd NOTIFY").readlines()
# omit friend request details and feed result into a the "self.fb" dictionary
for i in fblist:
ii = i.split()
try:
number = int(ii[-1])
self.fb[ii[0]] = number
except:
pass
print self.fb

def get_config(self,keyfile):
print "...getting user-configuration"
# get user configuration:
## which notifications should be added to counter?
self.config['MESSAGES_UNREAD'] = keyfile.getboolean('Configuration', 'MESSAGES_UNREAD')
self.config['POKES'] = keyfile.getboolean('Configuration', 'POKES')
self.config['SHARES_UNREAD'] = keyfile.getboolean('Configuration', 'SHARES_UNREAD')
self.config['FRIEND_REQUESTS'] = keyfile.getboolean('Configuration', 'FRIEND_REQUESTS')
self.config['GROUP_INVITES'] = keyfile.getboolean('Configuration', 'GROUP_INVITES')
self.config['EVENT_INVITES'] = keyfile.getboolean('Configuration', 'EVENT_INVITES')
## how often should notifications be checked?
self.config['REFRESH'] = keyfile.getint('Configuration', 'REFRESH')
self.timer = self.config['REFRESH'] * 6
## when should user be notified?
self.config['ATTENTION_WHEN'] = keyfile.get('Configuration', 'ATTENTION_WHEN')
print self.config

def begin(self):
# retrieve data from faceBook
self.read_fb()
self.set_counter()
print "...summoning countdown"
countdown(5, self)

def set_counter(self):
print "...setting counter"
# counting the current value for counter
new_counter = 0
for i in self.config:
# omitting non-boolean values from the config
if self.config[i].__class__ != bool:
pass
# omitting disabled notifications
elif self.config[i] == False:
pass
# remains enabled notifications
# adding their value to current value of counter
else:
new_counter += self.fb[i]
# record difference between current and prior counter
diff = self.counter - new_counter
# set counter to current value if != 0
self.counter = new_counter
if self.counter != 0:
self.icon.SetQuickInfo(format(self.counter))
else:
pass
# check if attention is needed
att = self.config["ATTENTION_WHEN"]
if att == "always" and self.counter != 0:
self.icon.DemandsAttention(True,"bounce")
time.sleep(2)
self.icon.DemandsAttention(False,"bounce")
elif att == "different" and diff != 0:
self.icon.Animate("bounce",4)
elif att == "superior" and diff > 0:
self.icon.Animate("bounce",4)
else:
pass
##### callbacks #####
def on_click(self, iState):
print "You have", self.counter, "unread message(s) on your faceBook account."
############
### main ###
############
if __name__ == '__main__':
Applet().run()

I don't know what the issue is here :confused:

Cheers,
Benjamin

[jesuisbenjamin]

I worked on it and looked into documentation, invariably, as I make a test application it works fine, but when I apply it to the Applet it doesn't... :(
I have changed the code to adding a "t" attribute, which is an instance of threading.Timer() this way i'll be able to t.start() or t.stop() anytime.
Also i made the loop between three functions. The countdown() function goes past the t.start() and prints "...thread initiated". Then i am not sure whether t really is running, but the target function reached() is not initiated, so that would mean t.start() fails: but why don't i get an error message then? Any help is welcome :) Cheers!

Here is the

#!/usr/bin/python

# This is a part of the external applets for Cairo-Dock
# Copyright : (C) 2011 by Benjamin
# E-mail : jesuisbenjamin@...
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# http://www.gnu.org/licenses/licenses.html#GPL
#
# This program depends on fbcmd, a command line interface (CLI) for facebook.
# http://fbcmd.dtompkins.com/

####################
### dependancies ###
####################

from CDApplet import CDApplet
import os
import threading
import time


####################
### Applet class ###
####################
class Applet(CDApplet):
def __init__(self):
# define internal variables:
# counter to display
self.counter = 1
# data retrieved from faceBook with fbcmd
self.fb = {}
# timer before refreshing data
self.timer = 5
# Timer thread
self.t = threading.Timer(self.timer, self.reached, [])
# call high-level init
CDApplet.__init__(self)

##### private methods #####
def read_fb(self):
print "...reading data from faceBook"
# run the "fbcmd NOTIFY" command and return and parse result in "fblist" list
fblist = os.popen("fbcmd NOTIFY").readlines()
# omit friend request details and feed result into a the "self.fb" dictionary
for i in fblist:
ii = i.split()
try:
number = int(ii[-1])
self.fb[ii[0]] = number
except:
pass
print self.fb

def get_config(self,keyfile):
print "...getting user-configuration"
# get user configuration:
## which notifications should be added to counter?
self.config['MESSAGES_UNREAD'] = keyfile.getboolean('Configuration', 'MESSAGES_UNREAD')
self.config['POKES'] = keyfile.getboolean('Configuration', 'POKES')
self.config['SHARES_UNREAD'] = keyfile.getboolean('Configuration', 'SHARES_UNREAD')
self.config['FRIEND_REQUESTS'] = keyfile.getboolean('Configuration', 'FRIEND_REQUESTS')
self.config['GROUP_INVITES'] = keyfile.getboolean('Configuration', 'GROUP_INVITES')
self.config['EVENT_INVITES'] = keyfile.getboolean('Configuration', 'EVENT_INVITES')
## how often should notifications be checked?
self.config['REFRESH'] = keyfile.getint('Configuration', 'REFRESH')
self.timer = self.config['REFRESH'] * 6
## when should user be notified?
self.config['ATTENTION_WHEN'] = keyfile.get('Configuration', 'ATTENTION_WHEN')
print self.config

def countdown(self):
self.t.start()
print "...initiating thread"

def reached(self):
print "...thread achieved"
self.countdown()

def begin(self):
# retrieve data from faceBook
self.read_fb()
self.set_counter()
print "...summoning countdown"
self.countdown()

def set_counter(self):
print "...setting counter"
# counting the current value for counter
new_counter = 0
for i in self.config:
# omitting non-boolean values from the config
if self.config[i].__class__ != bool:
pass
# omitting disabled notifications
elif self.config[i] == False:
pass
# remains enabled notifications
# adding their value to current value of counter
else:
new_counter += self.fb[i]
# record difference between current and prior counter
diff = self.counter - new_counter
# set counter to current value if != 0
self.counter = new_counter
if self.counter != 0:
self.icon.SetQuickInfo(format(self.counter))
else:
pass
# check if attention is needed
att = self.config["ATTENTION_WHEN"]
if att == "always" and self.counter != 0:
self.icon.DemandsAttention(True,"bounce")
time.sleep(2)
self.icon.DemandsAttention(False,"bounce")
elif att == "different" and diff != 0:
self.icon.Animate("bounce",4)
elif att == "superior" and diff > 0:
self.icon.Animate("bounce",4)
else:
pass
##### callbacks #####
def on_click(self, iState):
print "You have", self.counter, "unread message(s) on your faceBook account."
############
### main ###
############
if __name__ == '__main__':
Applet().run()

[jesuisbenjamin]

OK imma post another time with another update. I've tried to turn it in every way possible, but i didn't find a way to make it work. However i've been able to trace the event when the difficulty occurs: it seems that loading the Applet() instance freezes running threads, which finish only when killing the Applet.
For those who are interested to look into this i've made a dummy Cairo Applet showing this behaviour (start up Cairo with terminal). You can download this applet from here (http://dl.free.fr/pxkNEZ5SF).

Here is a copy of the Dummy script:

#!/usr/bin/python



####################
### dependancies ###
####################

from CDApplet import CDApplet
import threading
import time


class MakeApplet(threading.Thread):
def run(self):
print "...thread 04 making applet!"
facebook = Applet()
facebook.run()
time.sleep(3)
print "...facebook applet should be initiated!"

class MyThread(threading.Thread):
def run(self):
print("%s started!" % self.getName())
time.sleep(3)
print("%s finished!" % self.getName())

class Applet(CDApplet):
def __init__(self):
CDApplet.__init__(self)
##### private methods #####

def begin(self):
print "...It's alive!"


if __name__ == '__main__':
thread01 = MyThread(name= "Thread 01")
thread01.start()
time.sleep(1)
thread02 = MyThread(name= "Thread 02")
thread02.start()
time.sleep(1)
thread03 = MyThread(name= "Thread 03")
thread03.start()
time.sleep(1)
thread04 = MakeApplet()
thread04.start()

[jesuisbenjamin]

Yes i found my solution! Thanks to this blog (http://www.jejik.com/articles/2007/01/python-gstreamer_threading_and_the_main_loop/) and that documentation (http://wiki.python.org/moin/DbusExamples).

In short Gobject must allow threading with gobject.threads_init()

[cgroza]

Bravo...