GEN3: don't crash on overwritten msg in the receive buffer

app/src/async_stream.py

@@ -147,6 +147,7 @@ class AsyncStream():
                 logger.error(
                     f"Exception for {self.addr}:\n"
                     f"{traceback.format_exc()}")
+            await asyncio.sleep(0)  # be cooperative to other task
 
     async def async_write(self, headline: str = 'Transmit to ') -> None:
         """Async write handler to transmit the send_buffer"""

app/src/gen3/talent.py

@@ -294,6 +294,13 @@ class Talent(Message):
         result = struct.unpack_from('!lB', buf, 0)
         msg_len = result[0]    # len of complete message
         id_len = result[1]    # len of variable id string
+        if id_len > 17:
+            logger.warning(f'len of ID string must == 16 but is {id_len}')
+            self.inc_counter('Invalid_Msg_Format')
+
+            # erase broken recv buffer
+            self._recv_buffer = bytearray()
+            return
 
         hdr_len = 5+id_len+2