I am using glade as my gui and creating a process to run my gui in. This app will open a socket when 'on' is clicked. When i press 'send', it will send whatever is in an textfield to the socket. The socket receives this data and sends it back. The problem is after i send data to the socket the thread doesn't terminate. Also after i close my gui it calls a sys.exit() but also leaves a process and doesn't terminate. I believe the error is in how i am implementing my processes or all my processing in general. Can anyone shine some light on this? It also relates to my last post as well. Thanks
main.py
// Main thread that create a new process for my gui and displays it
import socket, thread, gtk, Handler, sys, os, multiprocessing
sys.setrecursionlimit(10000)
if __name__ == '__main__':
builder = gtk.Builder()
#32bit template.glade 64bit template-2.22
# @todo add switching between architectures
#
builder.add_from_file("template/template-2.22.glade")
builder.connect_signals(Handler.Handler(builder))
window = builder.get_object("window1")
window.show_all()
try:
p = multiprocessing.Process(target=gtk.main())
p.start()
except:
print "Error Starting new Thread"
handler.py
// Handler for gtk glade signals, creates new threads and handles button and stuff
import thread, threading, os, server, client,multiprocessing, time
import sys, gtk
class Handler(object):
'''
classdocs
'''
myobject = ''
def __init__(self,object1):
#Getting glade builder
self.myobject = object1
'''
Constructor
'''
def clickme(self,value):
myserver = server.Server()
try:
p = multiprocessing.Process(target=myserver.run)
p.start()
except:
pass
def sendmessage(self,value):
text = self.myobject.get_object('entry1').get_text()
print text
msg = client.MyClass()
p = multiprocessing.Process(target=msg.run,args=([text]))
p.start()
server.py
// Opens a socket and listens for incoming data and sends it back
import socket,multiprocessing, gtk, sys
class Server:
'''
classdocs
'''
def __init__(self):
'''
Constructor
'''
def run(self):
try:
while 1:
HOST = 'localhost' # Symbolic name meaning the local host
PORT = 50006 # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((HOST, PORT))
s.listen(5)
conn, addr = s.accept()
print 'Connected by', addr
while True:
data = conn.recv(1024)
if not data:
conn.close()
sys.exit()
break
elif data != '':
conn.sendall(data)
break
print "Closing"
#conn.close()
finally:
print "End"
pass
client.py
// Sends whatever is inside text area to socket
import time
class MyClass:
'''
classdocs
'''
def __init__(self):
'''
Constructor
'''
def run(self,text):
try:
import socket
HOST = 'localhost' # The localhost
PORT = 50006 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send(text)
data = s.recv(1024)
while 1:
if data != '':
print 'Received', repr(data)
break
finally:
pass
This is just wrong:
p = multiprocessing.Process(target=gtk.main())
p.start()
First, you can't start the gtk main loop in a subprocess, even if you did it rigth. Fortunately the process never really tries to start main
as you call gtk.main()
, which will block until the main loop exits and then return None
. So what you're actually doing is:
gtk.main()
p = multiprocessing.Process(target=None)
p.start()
Througout the rest of your code you keep creating new processes and then forgetting about them. If you would keep a reference to them, you could at least try to send the TERM
signal to them to shut them down (using Process.terminate
, or set the daemon
flag). If you want to shut down the subprocess cleanly, you either need to handle that signal in the subprocess, or use other IPC mechanisms to get it to shut down cleanly (like mutliprocessing.Event
, ...).
Then there is this:
while True:
data = conn.recv(1024)
if not data:
conn.close()
sys.exit()
break
elif data != '':
conn.sendall(data)
break
This while loop will never loop (unless recv
magically returns something else then a string). The first execution path ends with sys.exit()
(taking the whole server down - the break is unreachable), the second ends with break
, so the loop is useless.
A few lines below you have the exact opposite:
data = s.recv(1024)
while 1:
if data != '':
print 'Received', repr(data)
break
Unless data
was ''
in the first line, this will be an endless loop, as data
's value won't change anymore.
Generally you don't really need multiprocessing for most of this. Starting a server in a different process may be ok if if has to do a lot of work, but spawing a subprocess just to send some data is overkill. Sending and receiving using sockets are IO bound, using threading here would be more reasonable.
You have two classes (Server
and Handler
) which have only two methods, one of which is __init__
, and the other one is only used as target for a subprocess:
myserver = server.Server()
try:
p = multiprocessing.Process(target=myserver.run)
and:
msg = client.MyClass()
p = multiprocessing.Process(target=msg.run,args=([text]))
That's a sign that these shouldn't be classes but functions.