Add a keep-alive and timeout demo to the examples.

README.md

@@ -206,7 +206,8 @@ It responds to:
   * TCP connections on port 6970 (`socat stdio tcp4-connect:192.168.69.1:6970 <<<"abcdefg"`),
     where it will respond with reversed chunks of the input indefinitely.
   * TCP connections on port 6971 (`socat stdio tcp4-connect:192.168.69.1:6971 </dev/urandom`),
-    which will sink data.
+    which will sink data. Also, keep-alive packets (every 1 s) and a user timeout (at 2 s)
+    are enabled on this port; try to trigger them using fault injection.
   * TCP connections on port 6972 (`socat stdio tcp4-connect:192.168.69.1:6972 >/dev/null`),
     which will source data.
 

examples/server.rs

@@ -147,7 +147,9 @@ fn main() {
         {
             let socket: &mut TcpSocket = sockets.get_mut(tcp3_handle).as_socket();
             if !socket.is_open() {
-                socket.listen(6971).unwrap()
+                socket.listen(6971).unwrap();
+                socket.set_keep_alive(Some(1000));
+                socket.set_timeout(Some(2000));
             }
 
             if socket.may_recv() {