[SOLVED] How to measure the time elapsed since the last message received from a datagram socket in Poco C++?

How to measure the time elapsed since the last message received from a datagram socket in Poco C++?

My code monitors a datagram socket (implemented in the Poco framework), and I'd like to get notified if there were no messages received after a certain time. I have an infinite loop to monitor the socket, but the loop stops at receiveFrom() function, if no messages were received.

Here is the code:

#include <iostream>
#include <string>

//Poco includes
#include "Poco/Net/DatagramSocket.h"
#include "Poco/Net/SocketAddress.h"

int port = 5000;

Poco::Net::SocketAddress sa(Poco::Net::IPAddress(), port);
Poco::Net::DatagramSocket dgs(sa, true);
char buffer[1024];

for (;;)
    {
        int n = dgs.receiveFrom(buffer, sizeof(buffer)-1, sender);
        buffer[n] = '\0';
        std::string line = buffer;

        //Do something with the message

    };

Solution

You should set a timeout on your Poco socket.

Poco::Timespan wait_time( 10000 ); // microseconds

// from header file  Poco/Net/Socket.h
sa.getReceiveTimeout( wait_time )

Then check the number of bytes returned by receiveFrom(..) is > 0 or check for a timeout exception. Use this opportunity to do your other work.