lf_interop_throughput.py: Added max attempt at checking CXs

Added max_retries to cx states loop to avoid infinite checking if error
occurs.

Verified with:
./lf_interop_throughput.py --mgr 192.168.91.50 --mgr_port 8080 --ssid Quincefruit --passwd lanforge --security wpa2 --upstream_port 1.050.01 --traffic_type lf_udp --download 100000000 --test_duration 1m --packet_size 1500 --incremental_capacity 1 --precleanup --postcleanup

Signed-off-by: Cameron LaPlante <[email protected]>

Author: claplante-candela

py-scripts/lf_interop_throughput.py

@@ -655,8 +655,10 @@ def monitor(self, iteration, individual_df, device_names, incremental_capacity_l
         logger.info("Waiting for cx to start")
 
         # loop to get_cx_states until one return 'Running'
+        max_retries = 20
         cx_states_down = True
         while cx_states_down:
+            max_retries -= 1
             states = self.get_cx_states(list(self.cx_profile.created_cx.keys()))
             logger.info("states: {}".format(states))
 
@@ -665,6 +667,10 @@ def monitor(self, iteration, individual_df, device_names, incremental_capacity_l
                     cx_states_down = False
             time.sleep(2)
 
+            if max_retries == 0:
+                logger.error("CXs are not coming up. Exiting the test")
+                exit(1)
+
         start_time = datetime.now()
         logger.info("Monitoring cx and endpoints")
         end_time = start_time + timedelta(seconds=int(self.test_duration))