fix race condition reseting a default controller

dls-controls · Nov 14, 2016 · a4ce8fc · a4ce8fc
1 parent e15580c
commit a4ce8fc
Showing 1 changed file with 9 additions and 5 deletions.
diff --git a/malcolm/parts/builtin/childpart.py b/malcolm/parts/builtin/childpart.py
@@ -42,12 +42,16 @@ def store_params(self, params):
 
     @ManagerController.Reset
     def reset(self, task):
-        # Wait until we have finished resetting
-        state = self.child.state
-        if state == sm.RESETTING:
-            task.when_matches(self.child["state"], sm.READY)
-        elif state != sm.READY:
+        # Wait until we are READY
+        try:
             task.post(self.child["reset"])
+        except ValueError:
+            # We get a "ValueError: child is not writeable" if we can't run
+            # reset, probably because the child is already resetting,
+            # so just wait for it to be ready
+            task.when_matches(
+                self.child["state"], sm.READY, bad_values=[sm.FAULT])
+
 
     @ManagerController.ReportOutports
     def pre_layout(self, _):