From f9b02f34861e3b3fb6afe9b961f09200aab2c35b Mon Sep 17 00:00:00 2001
From: Stefan Allius <stefan.allius@t-online.de>
Date: Sun, 16 Jun 2024 11:56:03 +0200
Subject: [PATCH] add a close handler to release internal resources

---
 app/src/modbus.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/app/src/modbus.py b/app/src/modbus.py
index 8f3778b..fdb7c24 100644
--- a/app/src/modbus.py
+++ b/app/src/modbus.py
@@ -105,7 +105,16 @@ class Modbus():
         self.req_pend = False
         self.tim = None
 
+    def close(self):
+        """free the queue and the callback handler"""
+        logging.debug('Modbus close:')
+        self.rsp_handler = None
+        self.snd_handler = None
+        while not self.que.empty:
+            self.que.get_nowait()
+
     def __del__(self):
+        """log statistics on the deleting of a MODBUS instance"""
         logging.debug(f'Modbus __del__:\n {self.counter}')
 
     def build_msg(self, addr: int, func: int, reg: int, val: int,