L2SS-1987: Add test to check for race condition between push_change_event and Tango's polling loop

Closes L2SS-1987

tangostationcontrol/tangostationcontrol/common/events/change_events.py

@@ -62,5 +62,18 @@ class ChangeEvents:
             # self.device.push_change_event(attr_name, value, time.now(), AttrQuality.ATTR_INVALID, 0, 0)
             return
 
+        if (
+            self.device.is_attribute_polled(attr_name)
+            and self.device.get_attribute_poll_period(attr_name) > 0
+        ):
+            # Emitting an event now can cause a segfault in devices using the Asyncio green mode,
+            # if the Tango polling thread is accessing the same attribute we push an event for.
+            #
+            # See https://gitlab.com/tango-controls/cppTango/-/merge_requests/1316
+            # and https://gitlab.com/tango-controls/pytango/-/merge_requests/729
+            raise RuntimeError(
+                f"Cannot send change event for attribute {attr_name} of device {self.device} as it is already polled by Tango. Calling push_change_event can cause a Segmentation Fault."
+            )
+
         # emit any change
         self.device.push_change_event(attr_name, value)