Roomserver per-room input parallelisation (Postgres) (#1289)

* Per-room input mutex

* GetMembership should use transaction when assigning state key NID

* Actually use writer transactions rather than ignoring them

* Limit per-room mutexes to Postgres

* Flip the check in InputRoomEvents

1 files changed, 2 insertions, 2 deletions

diff --git a/roomserver/internal/api.go b/roomserver/internal/api.go
index 6d7c8fcf..efe9bdcd 100644
--- a/roomserver/internal/api.go
+++ b/roomserver/internal/api.go
@@ -20,7 +20,7 @@ type RoomserverInternalAPI struct {
 	ServerName           gomatrixserverlib.ServerName
 	KeyRing              gomatrixserverlib.JSONVerifier
 	FedClient            *gomatrixserverlib.FederationClient
-	OutputRoomEventTopic string     // Kafka topic for new output room events
-	mutex                sync.Mutex // Protects calls to processRoomEvent
+	OutputRoomEventTopic string   // Kafka topic for new output room events
+	mutexes              sync.Map // room ID -> *sync.Mutex, protects calls to processRoomEvent
 	fsAPI                fsAPI.FederationSenderInternalAPI
 }