Question

I want to do a simple thing: just bind two ports to wait for incoming connections and continous with the application code. This is the code.

import socket
import threading
import Queue

q = Queue.Queue()
q2 = Queue.Queue()

def escucha_9003():

    s = socket.socket()
    s.bind(("localhost",9023))
    s.listen(10) 
    sc, address = s.accept()
    q.put(sc)



def escucha_9004():

    s2 = socket.socket()
    s2.bind(("localhost",9024))
    s2.listen(10) 
    sc2, address2 = s2.accept()
    q.put(sc2)

hilo = threading.Thread(target=escucha_9003).start()
sc2=q.get()
hilo2 = threading.Thread(target=escucha_9004).start()
sc=q2.get()

print "i never arrive here"

I need to get some parameters that are returned in each function. I use Queue library to do it.
But the problem is that i want to keep working with the code and I never arrive to the line: print “i never arrive here”. At least it is never printed.

How need I do it to continue developing after launch those two threads and work with the incoming connections.

Thank you very much

Answer 1

Both .get() calls are blocking calls. Also, the .accept() calls in your threads are blocking. Technically you should never even get past the two .accept() calls if no connections are coming in from clients. Because the main thread is waiting on get() calls from the queues, but the queues never put anything because the threads are waiting on accepting a future connection.

What you would need to do is handle your queues from within threads instead of inside of the main thread. Otherwise, you will need to use .get(timeout=someSeconds) inside of an event loop where you keep checking for more stuff in your queues for a certain amount of time, and then move on to do more continuous processing.

You may want to explain exactly what you are trying to achieve, and then restructure these threads to handle a bit more of their own work before blocking the main thread to receive data.