scripts/python/app/NUT-Monitor-*.in, scripts/python/module/PyNUT.py.in: refactor with a graceful and harsher disconnect() handling [#3509]

Signed-off-by: Jim Klimov <jimklimov+nut@gmail.com>

Author: jimklimov

scripts/python/app/NUT-Monitor-py2gtk2.in

@@ -995,6 +995,10 @@ class gui_updater( threading.Thread ) :
                     self.__parent_class.gui_status_message( _("Connection lost - attempting to reconnect...") )
                     self.__parent_class.gui_status_notification( _("Connection lost"), "warning.png" )
 
+                    # Close the socket to avoid "Broken pipe" in subsequent calls if any
+                    if self.__parent_class._interface__ups_handler:
+                        self.__parent_class._interface__ups_handler.disconnect()
+
                     # Wait for 2 seconds before attempting reconnection
                     time.sleep( 2 )
                     self.__attempt_reconnect()

scripts/python/app/NUT-Monitor-py3qt5.in

@@ -1056,10 +1056,8 @@ class gui_updater :
                     self.__timer.stop()
 
                     # Close the socket to avoid "Broken pipe" in subsequent calls if any
-                    try:
-                        self.__parent_class._interface__ups_handler._PyNUTClient__srv_handler.close()
-                    except Exception:
-                        pass
+                    if self.__parent_class._interface__ups_handler:
+                        self.__parent_class._interface__ups_handler.disconnect()
 
                     # Schedule reconnection attempt after 2 seconds
                     QTimer.singleShot(2000, self.__attempt_reconnect)

scripts/python/app/NUT-Monitor-py3qt6.in

@@ -1079,10 +1079,8 @@ class gui_updater :
                     self.__timer.stop()
 
                     # Close the socket to avoid "Broken pipe" in subsequent calls if any
-                    try:
-                        self.__parent_class._interface__ups_handler._PyNUTClient__srv_handler.close()
-                    except Exception:
-                        pass
+                    if self.__parent_class._interface__ups_handler:
+                        self.__parent_class._interface__ups_handler.disconnect()
 
                     # Schedule reconnection attempt after 2 seconds
                     QTimer.singleShot(2000, self.__attempt_reconnect)

scripts/python/module/PyNUT.py.in

@@ -711,10 +711,20 @@ certhost    : Optional dict or list of dict/lists: {hostname: [certname, certver
     # Try to disconnect cleanly when class is deleted ;)
     def __del__( self ) :
         """ Class destructor method """
-        try :
-            self.__send( b"LOGOUT\n" )
-        except :
-            pass
+        self.disconnect()
+
+    def disconnect(self):
+        """ Disconnects from the server cleanly """
+        if hasattr(self, '__srv_handler') and self.__srv_handler:
+            try:
+                self.__send(b"LOGOUT\n")
+            except:
+                pass
+            try:
+                self.__srv_handler.close()
+            except:
+                pass
+            self.__srv_handler = None
 
     def __send(self, data):
         """ Internal method to send data through the socket with error handling """