Update comment

2017-05-03 10:00:29 +01:00 · 2017-05-03 10:00:29 +01:00 · e4435b014e
parent 871605f4e2
commit e4435b014e
1 changed files with 2 additions and 1 deletions
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@ -229,7 +229,8 @@ class StateStore(SQLBaseStore):

            # Prefill the state group cache with this group.
            # It's fine to use the sequence like this as the state group map
-            # is immutable.
+            # is immutable. (If the map wasn't immutable then this prefill could
+            # race with another update)
            txn.call_after(
                self._state_group_cache.update,
                self._state_group_cache.sequence,