python: keep event channel open until simulation object is released

Former-commit-id: a5281d31

Source/Python/dpsim/Simulation.py

@@ -60,6 +60,10 @@ class Simulation(_dpsim.Simulation):
         if pbar:
             self.show_progressbar()
 
+    def __del__(self):
+        self.remove_eventfd(self._event_socks[0].fileno())
+        self._events.close()
+
     def add_callback(self, cb, *args, event=None):
         self._events.add_callback(cb, *args, event=event)
 
@@ -79,9 +83,9 @@ class Simulation(_dpsim.Simulation):
         if self._pbar_tui:
             self._pbar_tui.finish()
 
-        self._pbar_task.cancel()
-        self.remove_eventfd(self._event_socks[0].fileno())
-        self._events.close()
+        if self._pbar_task:
+            self._pbar_task.cancel()
+
         LOGGER.info('Finished simulation!')
 
     def overrun(self, *args):