delete session update (#548)

ansys/dpf/core/server_types.py

@@ -369,6 +369,8 @@ def info(self):
         return self._base_service.server_info
 
     def _del_session(self):
+        if self._session_instance:
+            self._session_instance.delete()
         self._session_instance = None
 
     @property

ansys/dpf/core/session.py

@@ -133,6 +133,8 @@ def __init__(self, server=None):
         if server_meet_version("3.0", server):
             self.add_progress_system()
 
+        self._released = False
+
     @property
     def _server(self):
         return self._server_weak_ref()
@@ -202,8 +204,13 @@ def flush_workflows(self):
         """This removes the handle on the workflow by the ``session`` """
         self._api.flush_workflows(self)
 
-    def __del__(self):
+    def delete(self):
         try:
-            self._deleter_func[0](self._deleter_func[1](self))
+            if not self._released:
+                self._deleter_func[0](self._deleter_func[1](self))
         except:
             warnings.warn(traceback.format_exc())
+        self._released = True
+
+    def __del__(self):
+        self.delete()