Fixed #41. Timeout now raised when CF is not received after flow control without waiting on next CAN msg.

Author: pylessard

isotp/protocol.py

@@ -439,6 +439,9 @@ def process(self):
         Function to be called periodically, as fast as possible. 
         This function is non-blocking.
         """	
+
+        self.check_timeouts_rx()
+
         msg = True
         while msg is not None:
             msg = self.rxfn()
@@ -453,6 +456,12 @@ def process(self):
                 self.logger.debug("Sending : <%03X> (%d)\t %s" % (msg.arbitration_id, len(msg.data), binascii.hexlify(msg.data)))
                 self.txfn(msg)
 
+    def check_timeouts_rx(self):
+        # Check timeout first
+        if self.timer_rx_cf.is_timed_out():
+            self.trigger_error(isotp.errors.ConsecutiveFrameTimeoutError("Reception of CONSECUTIVE_FRAME timed out."))
+            self.stop_receiving()
+
     def process_rx(self, msg):
 
         if not self.address.is_for_me(msg):
@@ -466,11 +475,6 @@ def process_rx(self, msg):
             self.stop_receiving()
             return
 
-        # Check timeout first
-        if self.timer_rx_cf.is_timed_out():
-            self.trigger_error(isotp.errors.ConsecutiveFrameTimeoutError("Reception of CONSECUTIVE_FRAME timed out."))
-            self.stop_receiving()
-
         # Process Flow Control message
         if pdu.type == PDU.Type.FLOW_CONTROL:
             self.last_flow_control_frame = pdu 	 # Given to process_tx method. Queue of 1 message depth
@@ -587,7 +591,6 @@ def process_tx(self):
 
 
         # ======= FSM ======
-
         # Check this first as we may have another isotp frame to send and we need to handle it right away without waiting for next "process()" call
         if self.tx_state != self.TxState.IDLE and len(self.tx_buffer) == 0:
             self.stop_sending()	

test/test_transport_layer.py

@@ -235,19 +235,31 @@ def test_receive_multiframe_bad_seqnum(self):
         self.assertIsNone(self.get_tx_can_msg()) # Do not send flow control
         self.assert_error_triggered(isotp.WrongSequenceNumberError)
 
+    def test_receive_timeout_consecutive_frame_after_flow_control(self):
+        self.stack.params.set('rx_consecutive_frame_timeout', 200)
+
+        payload_size = 10
+        payload = self.make_payload(payload_size)
+        self.simulate_rx(data = [0x10, payload_size] + payload[0:6])
+        self.stack.process()
+        time.sleep(0.2) # Should stop receivving after 200 msec
+        self.stack.process()
+        self.assertIsNone(self.rx_isotp_frame())    # No message received indeed
+        self.assert_error_triggered(isotp.ConsecutiveFrameTimeoutError)
+
     def test_receive_timeout_consecutive_frame_after_first_frame(self):
         self.stack.params.set('rx_consecutive_frame_timeout', 200)
 
         payload_size = 10
         payload = self.make_payload(payload_size)
         self.simulate_rx(data = [0x10, payload_size] + payload[0:6])
         self.stack.process()
-        time.sleep(0.2)	# Should stop receivving after 200 msec
+        time.sleep(0.2) # Should stop receivving after 200 msec
         self.simulate_rx(data = [0x21] + payload[6:10])
         self.stack.process()
-        self.assertIsNone(self.rx_isotp_frame())	# No message received indeed
+        self.assertIsNone(self.rx_isotp_frame())    # No message received indeed
         self.assert_error_triggered(isotp.ConsecutiveFrameTimeoutError)
-        self.assert_error_triggered(isotp.UnexpectedConsecutiveFrameError)
+        self.assert_error_triggered(isotp.UnexpectedConsecutiveFrameError)        
 
     def test_receive_recover_timeout_consecutive_frame(self):
         self.stack.params.set('rx_consecutive_frame_timeout', 200)