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Multithreading - XMLRPC server registering class objects as individual threads in Python 2.7.12

From the server side, I have prepared a python script where the following tasks are performed.
Task 1 => Acquiring data from the sensors
Task 2 => Setting a certain register in the robot control unit to 1 or 0 depending upon the acquired data from the sensors
To do the above-mentioned tasks, i implemented two individual threads. To perform task 1, i have defined the class "SensorEvaluationBoard(Thread)" and for performing task 2 i have defined the class "UR_RTDE(Thread)". For more details, please see the following python script from the server side.
Server side:
#!/usr/bin/env python
import time
from time import sleep
import sys
import string
import traceback
import logging
import socket
import struct
import copy
import xmlrpclib
# xmlrpclib.Marshaller.dispatch[type(0L)] = lambda _, v, w: w("<value><i8>%d</i8></value>" % v)
# xmlrpclib.dumps((2**63-1,))
xmlrpclib.Binary
from SimpleXMLRPCServer import SimpleXMLRPCServer, SimpleXMLRPCRequestHandler
import threading
from threading import Thread, Lock
# "https://www.universal-robots.com/articles/ur-articles/real-time-data-exchange-rtde-guide/"
import rtde.rtde as rtde
import rtde.rtde_config as rtde_config
# urHost = "127.0.0.1" # UR robot's IP address
# "https://www.universal-robots.com/articles/ur-articles/remote-control-via-tcpip/"
urPort = 30004 # Port number dedicated for UR robot's secondary interface
config_filename = 'control_loop_configuration.xml'
mutexFreedriveMode = Lock()
loadCycleOfSensor1, loadCycleOfSensor2, loadCycleOfSensor3 = "", "", ""
c1, c2, c3 = 0, 0, 0
cnt = 0
data = bytearray()
sensEvalBoard_ipAddr = "" # IP address of sensor evaluation board
sensEvalBoard_port = 0 # Port number of of sensor evaluation board
DEFAULT_TIMEOUT = 1
mutexSensVal = Lock()
sebSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # initializing the socket object
mutexSEBSocket = Lock()
def set_ipaddr(new_daemon_host):
global sensEvalBoard_ipAddr
sensEvalBoard_ipAddr = new_daemon_host
return sensEvalBoard_ipAddr
def get_ipaddr():
tmp = ""
if str(sensEvalBoard_ipAddr):
tmp = sensEvalBoard_ipAddr
else:
tmp = "No ip address set"
return tmp
def set_portnum(new_daemon_port):
global sensEvalBoard_port
sensEvalBoard_port = int (new_daemon_port)
return sensEvalBoard_port
def get_portnum():
tmp = 0
if sensEvalBoard_port != 0:
tmp = sensEvalBoard_port
else:
tmp = 0
return tmp
class ConnectionState:
DISCONNECTED = 0
CONNECTED = 1
STARTED = 2
PAUSED = 3
class SensorEvaluationBoardException(Exception):
def __init__(self, msg):
self.msg = msg
def __str__(self):
return repr(self.msg)
class SensorEvaluationBoard(Thread):
def __init__(self, hostname, port):
# Call the Thread class's init function
Thread.__init__(self)
self.__hostname = hostname
self.__port = port
self.__conn_state = ConnectionState.DISCONNECTED
self.__sock = None
logging.basicConfig(level=logging.DEBUG)
self.__logger = logging.getLogger(self.__class__.__name__)
# self.__streamHandler = logging.StreamHandler()
# self.__streamHandler.setLevel(logging.DEBUG)
# self.__formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
# self.__streamHandler.setFormatter(self.__formatter)
# self.__logger.addHandler(self.__streamHandler)
def connect(self):
global sebSocket
if self.__sock:
return
self.__buf = b''
try:
self.__sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.__sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.__sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
self.__sock.settimeout(DEFAULT_TIMEOUT)
self.__sock.connect((self.__hostname, self.__port))
self.__conn_state = ConnectionState.CONNECTED
sebSocket = copy.deepcopy(self.__sock)
except (socket.timeout, socket.error):
self.__sock = None
raise
def disconnect(self):
if self.__sock:
self.__sock.close()
self.__sock = None
self.__conn_state = ConnectionState.DISCONNECTED
def is_connected(self):
return self.__conn_state is not ConnectionState.DISCONNECTED
def get_connection_state(self):
return self.__conn_state
def send_input_data(self, data):
self.__sock.send(data)
def receive_output_data(self, input_data):
self.send_input_data(input_data)
self.__rcvData = self.__sock.recv(1024)
return self.__rcvData
def run(self):
global loadCycleOfSensor1, loadCycleOfSensor2, loadCycleOfSensor3
self.connect()
while True:
if self.is_connected:
# print("Socket => connection state: " + str(self.get_connection_state()) + " means CONNECTED")
self.__input_data = bytearray()
self.__input_data.append(0x1)
self.__rcvData = self.receive_output_data(self.__input_data)
self.__unpacker_string = 3*'I I I I I B B B B'
self.__unpacker = struct.Struct('<B '+ self.__unpacker_string)
self.__unpacked = self.__unpacker.unpack(self.__rcvData)
# print("Slave 1: "+ repr(self.__unpacked[1:10]))
# print("Slave 2: "+ repr(self.__unpacked[10:19]))
# print("Slave 3: "+ repr(self.__unpacked[19:28]))
mutexSensVal.acquire()
loadCycleOfSensor1 = str(self.__unpacked[1])
loadCycleOfSensor2 = str(self.__unpacked[12])
loadCycleOfSensor3 = str(self.__unpacked[20])
# print("Load cycle of sensors 1, 2 and 3: ["+ loadCycleOfSensor1 + ", " + loadCycleOfSensor2 + ", " + loadCycleOfSensor3 + "]")
mutexSensVal.release()
sleep(0.1)
else:
print("Socket => connection state: " + str(self.get_connection_state()) + " means DISCONNECTED")
class UR_RTDE(Thread):
def __init__(self, host, port, config_filename):
# Call the Thread class's init function
Thread.__init__(self)
self.__host = host
self.__port = port
self.__config_filename = config_filename
logging.basicConfig(level=logging.DEBUG)
self.__logger = logging.getLogger(self.__class__.__name__)
# self.__streamHandler = logging.StreamHandler()
# self.__streamHandler.setLevel(logging.INFO)
# self.__formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
# self.__streamHandler.setFormatter(self.__formatter)
# self.__logger.addHandler(self.__streamHandler)
self.__con = None
self._rtde_ok = False
self._recept_ok = False
self._dataAccessConfig = Lock()
self.__keep_running = True
def init_rtde(self):
self.__logger.debug("init_rtde")
if not self._rtde_ok :
if self.__con is None:
self.connect_rtde()
if not self._recept_ok:
self.init_conf()
self.send_conf_to_robot()
self.start_communication()
self._rtde_ok = True
def connect_rtde(self):
self.__logger.debug("connect_rtde")
try:
self.__con = rtde.RTDE(self.__host, self.__port)
self.__con.connect()
except socket.timeout as e:
self.__logger.error("failed to connect with robot", exc_info=True)
self.__controller_info = None
self.__con = None
self.__controller_info = self.__con.get_controller_version()
self.__logger.info("connected with UR established")
self.__logger.info(self.__controller_info)
return True
def disconnect_rtde(self):
self.__con.send_pause()
self.__con.disconnect()
self.__logger.debug("disconnect_rtde")
def init_conf(self):
self.__logger.debug("init_conf")
with self._dataAccessConfig:
self._conf = rtde_config.ConfigFile(self.__config_filename)
self._state_names, self._state_types = self._conf.get_recipe('state')
self._set_freedrive_name, self._set_freedrive_type = self._conf.get_recipe('set_freedrive')
def send_conf_to_robot(self):
self.__logger.debug("send_conf_to_robot")
print("in send conf")
try:
self.__con.send_output_setup(self._state_names, self._state_types)
self.__set_freedrive = self.__con.send_input_setup(self._set_freedrive_name, self._set_freedrive_type)
self.__set_freedrive.__dict__[b"input_bit_register_64"] = 0
self._recept_ok = True
except Exception as e:
self.__set_freedrive = None
self.__logger.error("rtde recepts error", exc_info=True)
self._recept_ok = False
def start_communication(self):
self.__logger.debug("start_communication")
if not self.__con.is_connected():
self.__logger.warning("no connection established")
if not self.__con.send_start():
self.__logger.warning("starting data_sync failed")
sys.exit()
self.__logger.info("started communication")
return True
def run(self):
global loadCycleOfSensor1, loadCycleOfSensor2, loadCycleOfSensor3
global c1, c2, c3
lowerThr_loadCycleOfSensor1, upperThr_loadCycleOfSensor1 = 400, 700
lowerThr_loadCycleOfSensor2, upperThr_loadCycleOfSensor2 = 100, 400
lowerThr_loadCycleOfSensor3, upperThr_loadCycleOfSensor3 = 200, 425
lTh_c1 = lowerThr_loadCycleOfSensor1
uTh_c1 = upperThr_loadCycleOfSensor1
lTh_c2 = lowerThr_loadCycleOfSensor2
uTh_c2 = upperThr_loadCycleOfSensor2
lTh_c3 = lowerThr_loadCycleOfSensor3
uTh_c3 = upperThr_loadCycleOfSensor3
self.init_rtde()
# Set the 'input_bit_register_64' to 0 by default
self.__set_freedrive.__dict__[b"input_bit_register_64"] = 0
if self.__con.is_connected():
while self.__keep_running:
# receive the current state
self.__state = self.__con.receive()
if self.__state is None:
break
mutexSensVal.acquire()
c1 = int (loadCycleOfSensor1)
self.__logger.info("Loading cycle of CapSen1 is " + str(c1))
c2 = int (loadCycleOfSensor2)
self.__logger.info("Loading cycle of CapSen2 is " + str(c2))
c3 = int (loadCycleOfSensor3)
self.__logger.info("Loading cycle of CapSen3 is " + str(c3))
mutexSensVal.release()
mutexFreedriveMode.acquire()
# input_bit_register_64 refers to "general purpose input register 64"
# if "general purpose input register 64" variable is set to 1 => Freedrive mode is activated
if ((lTh_c1 < c1 < uTh_c1) and (lTh_c2 < c2 < uTh_c2)):
self.__set_freedrive.__dict__[b"input_bit_register_64"] = 1
self.__logger.info("Capacitive sensors 1 and 2 are touched by the human operator, Freedrive mode activated")
elif ((lTh_c2 < c2 < uTh_c2) and (lTh_c3 < c3 < uTh_c3)):
self.__set_freedrive.__dict__[b"input_bit_register_64"] = 1
self.__logger.info("Capacitive sensors 2 and 3 are touched by the human operator, Freedrive mode activated")
elif ((lTh_c3 < c3 < uTh_c3) and (lTh_c1 < c1 < uTh_c1)):
self.__set_freedrive.__dict__[b"input_bit_register_64"] = 1
self.__logger.info("Capacitive sensors 1 and 3 are touched by the human operator, Freedrive mode activated")
else:
self.__set_freedrive.__dict__[b"input_bit_register_64"] = 0
self.__logger.info("No two capacitive sensors are touched by the human operator, Freedrive mode deactivated")
self.__con.send(self.__set_freedrive)
mutexFreedriveMode.release()
sleep(0.1)
self.disconnect_rtde()
def main():
try:
# threadevent = threading.Event()
# Create an object of Thread
th_sensevalboard = SensorEvaluationBoard(sensEvalBoard_ipAddr, sensEvalBoard_port)
# start the SensorEvaluationBoard thread
th_sensevalboard.start()
sleep(1)
# Create an object of Thread
th_rtde = UR_RTDE(urHost, urPort, config_filename)
# start the RTDE thread
th_rtde.start()
return "SensorEvaluationBoard and RTDE threads has started..."
except KeyboardInterrupt:
print("Terminating communication with the sensor evaluation board... ")
th_sensevalboard.disconnect()
print("Socket => connection state: " + str(th_sensevalboard.get_connection_state()) + " means DISCONNECTED")
th_sensevalboard.join()
print ("SensorEvaluationBoard thread successfully closed")
print("Terminating communication with the RTDE server... ")
th_rtde.disconnect()
th_rtde.join()
print ("RTDE thread successfully closed")
return "SensorEvaluationBoard and RTDE threads has stopped..."
sys.stdout.write("CapSens daemon started")
sys.stderr.write("CapSens daemon started with caught exception")
# server_addr = ("127.0.0.1", 40405)
# server = SimpleXMLRPCServer(server_addr, SimpleXMLRPCRequestHandler, allow_none=True)
server = SimpleXMLRPCServer(("127.0.0.1", 40405), allow_none=True)
server.register_function(set_ipaddr, "set_ipaddr")
server.register_function(get_ipaddr, "get_ipaddr")
server.register_function(set_portnum, "set_portnum")
server.register_function(get_portnum, "get_portnum")
server.register_instance(UR_RTDE(urHost, urPort, config_filename), allow_dotted_names=True)
server.register_instance(SensorEvaluationBoard(sensEvalBoard_ipAddr, sensEvalBoard_port), allow_dotted_names=True)
server.register_function(main, "main")
server.serve_forever()
In the main() function of the above-mentioned python script, i initialize the two threads 'th_sensevalboard' and 'th_rtde' and start them one after the other. After the main() function, i tried to register the class objects which are individual threads as instances to an XMLRPC server. I am not sure, if this is the right way to do it.
Can anyone please have a look at the above-mentioned python script and tell me if the way in which i register multiple class objects which which are individual threads as instances to an XMLRPC server is proper or not? If it is not the proper way, can you please give me your suggestions.
Best Regards

too many file descriptors in select() python in windows

i am trying to receive about 1000 connections to my server but it cannot receive more than 512. What can i do to increase the amount of open connections? I am running windows 8.1
Not: I am very new to this stuff so, thanks for help
Here is my code;
import asyncore
import socket
import uuid
import time
import threading
class statistics(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
while True:
entry = raw_input("")
zaman = int(time.time())
cmd = receivedCmd
print "calculating.."
time.sleep(1)
if entry == 'istatistik':
print str(receivedCmd-cmd) + " command/second"
print "total received commands: " + str(receivedCmd)
entry = ""
class tcpClient:
def __init__(self):
self.clientid = uuid.uuid1(int(time.time()))
self.buffer = ""
self.buffer_size = 0
self.conn_time = time.time()
self.overflow = 0
#print str(self.clientid) + " assingned"
def recv_msg(self, msg):
global receivedCmd
self.buffer = msg
self.buffer_size = len(self.buffer)
receivedCmd = receivedCmd + 1
if self.buffer_size >= 1024:
self.overflow = 1
def __del__(self):
print str(self.clientid) + " has left."
class TCPHandler(asyncore.dispatcher_with_send):
global clist
def handle_read(self):
data = self.recv(1024)
if data:
if clist[self].overflow:
self.send("overflow")
self.handle_close()
else:
self.send(data)
clist[self].recv_msg(data)
def handle_close(self):
del clist[self]
self.close()
def handle_error(self):
del clist[self]
self.close()
class TCPServer(asyncore.dispatcher):
global clist
def __init__(self, host, port):
asyncore.dispatcher.__init__(self)
self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
self.set_reuse_addr()
self.bind((host, port))
self.listen(5)
def handle_accept(self):
self.clist = clist
pair = self.accept()
if pair is None:
pass
else:
sock, addr = pair
#print 'Connection : %s' % repr(addr)
clist[TCPHandler(sock)] = tcpClient()
if __name__ == '__main__':
clist = {}
receivedCmd = 0
server = TCPServer('', 5000)
server2 = TCPServer('',5001)
StaticsThread = statistics()
StaticsThread.start()
asyncore.loop()
Note: I still cannot receive more than 512 connections with the Twisted Framework, i don't know what to do. There have to be thousands of connected clients. Please help.

The asyncore module relies in the select OS function, which only supports a limited number of file descriptors.
As an alternative use a multi-threading server (I won't recommend this) or, better, the Twisted framework which is event-driven (highly recommended!).
Hope this helps!
Since Twisted's default reactor under Windows is also select-based then you should consider using the IOCP reactor instead.
from twisted.internet import iocpreactor
iocpreactor.install()
from twisted.internet import reactor
But also take into account that Twisted prefers Linux systems (where the default reactor is epoll-based) rather than Windows. Maybe switching to Linux is a better choice.

Python P2P Sockets Chat Script working only on home network (not on school network)

I have the following python script (a bit inefficient, I know) for a P2P chat program using sockets:
#!usr/bin/env python
import socket import threading import select import time import datetime
def main():
class Chat_Server(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
self.running = 1
self.conn = None
self.addr = None
def run(self):
HOST = ''
PORT = 23647
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((HOST,PORT))
s.listen(1)
self.conn, self.addr = s.accept()
# Select loop for listen
while self.running == True:
inputready,outputready,exceptready \
= select.select ([self.conn],[self.conn],[])
for input_item in inputready:
# Handle sockets
message = self.conn.recv(1024)
if message:
print "Daniel: " + message + ' (' + datetime.datetime.now().strftime('%H:%M:%S') + ')'
else:
break
time.sleep(0)
def kill(self):
self.running = 0
class Chat_Client(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
self.host = None
self.sock = None
self.running = 1
def run(self):
PORT = 23647
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.connect((self.host, PORT))
# Select loop for listen
while self.running == True:
inputready,outputready,exceptready \
= select.select ([self.sock],[self.sock],[])
for input_item in inputready:
# Handle sockets
message = self.sock.recv(1024)
if message:
print "Daniel: " + message + ' (' + datetime.datetime.now().strftime('%H:%M:%S') + ')'
else:
break
time.sleep(0)
def kill(self):
self.running = 0
class Text_Input(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
self.running = 1
def run(self):
while self.running == True:
text = raw_input('')
try:
chat_client.sock.sendall(text)
except:
Exception
try:
chat_server.conn.sendall(text)
except:
Exception
time.sleep(0)
def kill(self):
self.running = 0
# Prompt, object instantiation, and threads start here.
ip_addr = raw_input('Type IP address or press enter: ')
if ip_addr == '':
chat_server = Chat_Server()
chat_client = Chat_Client()
chat_server.start()
text_input = Text_Input()
text_input.start()
else:
chat_server = Chat_Server()
chat_client = Chat_Client()
chat_client.host = ip_addr
text_input = Text_Input()
chat_client.start()
text_input.start()
if __name__ == "__main__":
main()
This script works absolutely fine across a home network, with 192.168... internal IP addresses.
On a school network, with 172... IP addresses, it doesn't seem to work. There is no connection error, but messages are not sent or received, with the exception of if there are two instances of the application being run on the same computer with the same internal IP address, in which case the program works flawlessly.
I am very new to sockets and this sort of networking, so I am wondering if anyone can point out to me why this is the case. Might it be the difference in IP addresses, for example?
Thank you in advance.

I see you're connecting on port 23647 - you may not have access to this on your school network. Check if this port has traffic enabled. see: Port Forwarding for details.
Something like: this site/tool may allow you to check quickly.

zeromq: why dealer sends one message and receives from one client?

I'm trying to understand my code's behavior.
I'm using zeromq to create a server that sends a "ping" and waits for "pong" responses.
What i'm seeing is that when I send a ping, only one client receives it.
when I run this code and send "ping" for the first time i receive:
pong: A
and when i run it again, i get
pong: B
why is that? I want to send one "ping" and receive two pongs.
here's the code:
from threading import Thread
import zmq
class zmqdealer(object):
def __init__(self, port):
context = zmq.Context()
self.sock = context.socket(zmq.DEALER)
#self.sock.setsockopt(zmq.RCVTIMEO, 1000)
self.sock.bind("tcp://*:%s" % port)
thread = Thread(target=lambda: self.poll())
thread.daemon = True
thread.start()
def poll(self):
while True:
reply = self.sock.recv()
if reply != "":
print(reply)
def ping(self):
self.sock.send_multipart(['', 'ping'])
class zmqrep(object):
def __init__(self, ident,host, port):
context = zmq.Context()
self.sock = context.socket(zmq.REP)
self.sock.connect("tcp://%s:%s" % (host, port))
self.ident = ident
thread = Thread(target=lambda: self.pong())
thread.daemon = True
thread.start()
def pong(self):
while True:
request = self.sock.recv()
if request == "ping":
msg = "pong: %s" % self.ident
self.sock.send(msg)
if __name__ == "__main__":
port = 11112
host = "localhost"
server = zmqdealer(port)
client1 = zmqrep('A',host,port)
client2 = zmqrep('B',host,port)
answer = raw_input('press <ENTER> to exit or type \'ping\' to get a pong\n')
while True:
if answer == "":
break
if answer == "ping":
server.ping()
answer = raw_input()
EDIT
I found a way to make this work. I really hope there is another way because i genuinely hate this one! so it looks like dealer sends to the clients in a round robin fashion. so to make my ping work i had to send it to all the clients. how? i subscribed to the monitor socket and added every connected client to a list. every time i ping, i ping to every client. look:
import threading
import zmq
from zmq.utils import monitor
def threadify(func, daemon=True):
thread = threading.Thread(target=func)
thread.daemon = daemon
thread.start()
class zmqdealer(object):
def __init__(self, port):
context = zmq.Context()
self.sock = context.socket(zmq.DEALER)
self.monitor_sock = self.sock.get_monitor_socket()
self.sock.bind("tcp://*:%s" % port)
self.connected_clients = {}
threadify(func=self.poll)
threadify(func=self.monitor)
def poll(self):
while True:
reply = self.sock.recv()
if reply != "":
print reply
def add_client(self, event):
endpoint = event['endpoint']
value = event['value']
if endpoint in self.connected_clients:
self.connected_clients[endpoint].append(value)
else:
self.connected_clients[endpoint] = [value]
def remove_client(self, event):
endpoint = event['endpoint']
value = event['value']
if endpoint in self.connected_clients \
and value in self.connected_clients[endpoint]:
self.connected_clients[endpoint].remove(value)
def monitor(self):
options = {zmq.EVENT_ACCEPTED: lambda e: self.add_client(e),
zmq.EVENT_DISCONNECTED: lambda e: self.remove_client(e)}
while True:
event = monitor.recv_monitor_message(self.monitor_sock)
event_type = event['event']
if event_type in options:
options[event_type](event)
event['event'] = event_types[event_type]
print event
def ping(self):
connected_clients_amount = sum([len(clients) for clients in self.connected_clients.values()])
for i in xrange(connected_clients_amount):
self.sock.send_multipart(['', 'ping'])
if connected_clients_amount <= 0:
print "there are no connected clients!"
class zmqrep(object):
def __init__(self, ident, host, port):
context = zmq.Context()
self.sock = context.socket(zmq.REP)
self.sock.connect("tcp://%s:%s" % (host, port))
self.identity = ident
self.stopped = threading.Event()
threadify(self.pong)
def pong(self):
while not self.stopped.isSet():
request = self.sock.recv()
if request == "ping":
msg = "pong: %s" % self.identity
self.sock.send(msg)
self.sock.close()
def stop(self):
self.stopped.set()
if __name__ == "__main__":
port = 11112
host = "localhost"
num = 5
server = zmqdealer(port)
clients = [zmqrep(i.__str__(), host, port) for i in xrange(num)]
answer = raw_input('press <ENTER> to exit or type \'ping\' to get a pong\n')
while True:
if answer == "":
break
if answer == "ping":
server.ping()
if answer == "kill":
if len(clients) > 0:
die = clients[0]
clients.remove(die)
die.stop()
else:
print "there are no connected clients!\n"
answer = raw_input()

Router/Dealer sockets are best used for distributing tasks. Say you have 10 tasks and 2 workers, you do not care who does what. Dealer/Router will distribute in a round robin fashion.
Maybe Pub/Sub or Push/Pull sockets would fit your usecase better? They are both broadcast sockets.
Here's an example of Push/Pull used in a similar fashion as what you're doing.
You often end up doing pairs of sockets, one to transmit and one other to receive results. You could for example do a PUSH with a ping message + random identifier, and ask clients to answer on PUB/SUB where you subscribe to this random identifier. This way you can match requests and responses.

Socket in python will only send data it receives

I must be missing something in the code. I've rewritten an 'echo server' example to do a bit more when it receives something.
This is how it currently looks:
#!/usr/bin/env python
import select
import socket
import sys
import threading
import time
import Queue
globuser = {}
queue = Queue.Queue()
class Server:
def __init__(self):
self.host = ''
self.port = 2000
self.backlog = 5
self.size = 1024
self.server = None
self.threads = []
def open_socket(self):
try:
self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.server.bind((self.host,self.port))
self.server.listen(5)
except socket.error, (value,message):
if self.server:
self.server.close()
print "Could not open socket: " + message
sys.exit(1)
def run(self):
self.open_socket()
input = [self.server,sys.stdin]
running = 1
while running:
inputready,outputready,exceptready = select.select(input,[],[])
for s in inputready:
if s == self.server:
# handle the server socket
c = Client(self.server.accept(), queue)
c.start()
self.threads.append(c)
elif s == sys.stdin:
# handle standard input
junk = sys.stdin.readline()
running = 0
# close all threads
self.server.close()
for c in self.threads:
c.join()
class Client(threading.Thread):
initialized=0
def __init__(self,(client,address), queue):
threading.Thread.__init__(self)
self.client = client
self.address = address
self.size = 1024
self.queue = queue
self.threads = []
global globuser
print 'Client thread created!'
def run(self):
running = 1
while running:
print 'While running client'
data = self.client.recv(self.size)
print 'Dit we receive data?'
if data:
print 'Data received!'
print 'Fetching data from socket: ',
if data[0] == 'I':
print 'Initializing user: ' + data
user = {'uid': data[1:6] ,'x': data[6:9], 'y': data[9:12]}
globuser[user['uid']] = user
print globuser
initialized=1
m=updateClient(user['uid'], queue)
m.start()
self.threads.append(m)
self.client.send('Beginning - Initialized'+';')
elif data[0] == 'A':
print 'Client has received previous data: ' + data
#On deactivation, nothing works.
self.client.send(data+';')
#print 'Client Data sent: ' + data
else:
print 'Closing'
self.client.close()
running = 0
if self.queue.empty():
print 'Queue is empty'
else:
print 'Queue has information: ',
data2 = self.queue.get(1, 1)
isdata2 = 1
if data2 == 'Exit':
running = 0
print 'Client is being closed'
self.client.close()
if isdata2 == 1:
print 'Sending data to client: ' + data2,
self.client.send(data2)
self.queue.task_done()
isdata2 = 0
time.sleep(1)
class updateClient(threading.Thread):
def __init__(self,uid, queue):
threading.Thread.__init__(self)
self.uid = uid
self.queue = queue
global globuser
print 'updateClient thread started!'
def run(self):
running = 20
test=0
while running > 0:
test = test + 1
self.queue.put('Test Queue Data #' + str(test))
running = running - 1
time.sleep(1)
print 'Updateclient has stopped'
if __name__ == "__main__":
s = Server()
s.run()
This runs fine, although it's kind of silly to keep sending the same data back again along with other data.
In the middle of the code you'll see
#On deactivation, nothing works.
self.client.send(data+';')
#print 'Client Data sent: ' + data
When I DO deactive the self.client.send(data+';') or change it into self.client.send('something else;') it does not work! And the client receives nothing.
Is there something special about the "data" variable? Do I need to format the string in some way?

Here's a cleaned-up, functional version of your code! I tested it myself, though I didn't write unit tests.
There were some syntax errors and other miscellaneous problems with the
original code, so I took some liberties. I'm assuming that the protocol is
framed by using ; as a delimiter, since a ; is sent at the end of every
message to the client, though no framing was being done in the original code.
from twisted.internet import reactor, protocol, task
from twisted.protocols import basic
from twisted.python import log
import sys
class ServerProtocol(basic.LineOnlyReceiver):
delimiter = ';'
def lineReceived(self, line):
if line.startswith('I'):
user = dict(uid=line[1:6], x=line[6:9], y=line[9:12])
self.factory.users[user['uid']] = user
log.msg(repr(self.factory.users))
self.startUpdateClient()
self.sendLine('Beginning - Initialized')
elif line.startswith('A'):
self.sendLine(line)
else:
self.transport.loseConnection()
def _updateClient(self):
if self._running == 0:
self._looper.stop()
return
self._running -= 1
self._test += 1
self.sendLine('Test Queue Data #%d' % (self._test,))
def startUpdateClient(self):
self._running, self._test = 20, 0
self._looper = task.LoopingCall(self._updateClient)
self._looper.start(1, now=False)
class Server(protocol.ServerFactory):
protocol = ServerProtocol
def __init__(self):
self.users = {}
if __name__ == '__main__':
log.startLogging(sys.stderr)
reactor.listenTCP(2000, Server())
reactor.run()