Optimise createRoom with multiple invites (#8559)

By not dropping the membership lock between invites, we can stop joins from
grabbing the lock when we're half-done and slowing the whole thing down.

1 files changed, 6 insertions, 2 deletions

diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index ec784030e9..7cd858b7db 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -307,7 +307,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         key = (room_id,)
 
         with (await self.member_linearizer.queue(key)):
-            result = await self._update_membership(
+            result = await self.update_membership_locked(
                 requester,
                 target,
                 room_id,
@@ -322,7 +322,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
 
         return result
 
-    async def _update_membership(
+    async def update_membership_locked(
         self,
         requester: Requester,
         target: UserID,
@@ -335,6 +335,10 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         content: Optional[dict] = None,
         require_consent: bool = True,
     ) -> Tuple[str, int]:
+        """Helper for update_membership.
+
+        Assumes that the membership linearizer is already held for the room.
+        """
         content_specified = bool(content)
         if content is None:
             content = {}