Ctrl +C shutdown for a blocking call

edit

Hello,

Inside my loop

while(ros::ok())
{
// do blocking recvfrom socket
// receives data from socket
recvfrom(s, _buf, buf_size_, 0, (struct sockaddr *) &si_other, &slen);
...

ros::spinOnce();

}

This code work perfectly and the ROS_INFO shows that is receives data from socket port correctly. NOTE here the incoming data is outside ros node. But when I exit using Ctrl+C. The node does not exit. The result is I have to force shutdown. This causes my port to connected. netstat shows the port is still in use. however rosnode list shows that the node has shutdown. This is likely because the code is stuck at the blocking call recvfrom. Any suggestion to overcome this ?

My question is similar to

http://answers.ros.org/question/31570...

But the suggestion spinOnce didnt help