Terminate a sockert.recv in a thread in Python

Question

Hello,

To implement a simple protocol in python, I've used a thread to monitor acknowledgements send by the receiver. To do this, I use a thread in a function

def ackListener(self):

    while self.waitingforack:
        ack = self.socket_agent.recv(4)
        ...
    exit()

where self.waitingforack is a boolean I set to False when I've received an acknowledgement for every messages I've sent.

The problem is that my code is blocking at the self.socket_agent.recv(4) operation, the modification of the value of waitingforack is done too late

Is there a way to force the Thread to terminate when I'm not waiting for ack anymore ?

Thank you

Answer 1

Remember that these operations like recv are blocking operations in your case. So calling this function blocks unless you have received the data.

There are two ways to go about it:

Make socket non blocking

socket.setblocking(0)

Set a timeout value see : http://docs.python.org/library/socket.html#socket.socket.settimeout

socket.settimeout(value)

Use asynchronous approach

• http://docs.python.org/library/asyncore.html