merge mercury branch; release v3.8.0

Author: anla-xu

demo/Server_A1.py

@@ -63,6 +63,7 @@ def __init__(self, host, port, serial_num="/dev/ttyAMA1", baud=115200):
         self.serial_num = serial_num
         self.baud = baud
         self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         self.s.bind((host, port))
         print("Binding succeeded!")
         self.s.listen(1)
@@ -98,13 +99,15 @@ def connect(self):
                                     "return datas: {}".format([hex(v) for v in res]))
 
                                 conn.sendall(res)
+                    except ConnectionResetError:
+                        print("close disconnect!")
+                        time.sleep(0.1)
                     except Exception as e:
                         self.logger.error(traceback.format_exc())
-                        conn.sendall(str.encode(traceback.format_exc()))
                         break
             except Exception as e:
                 self.logger.error(traceback.format_exc())
-                conn.close()
+                self.conn.close()
                 self.mc.close()
 
     def _encode_int16(self, data):