Use a more reliable method of reviving the update thread realm after blocking

osu.Game/Database/RealmContextFactory.cs

@@ -69,9 +69,9 @@ namespace osu.Game.Database
 
         private Realm? context;
 
-        public Realm Context
-        {
-            get
+        public Realm Context => ensureUpdateContext();
+
+        private Realm ensureUpdateContext()
         {
             if (!ThreadSafety.IsUpdateThread)
                 throw new InvalidOperationException(@$"Use {nameof(createContext)} when performing realm operations from a non-update thread");
@@ -94,7 +94,6 @@ namespace osu.Game.Database
                 return context;
             }
         }
-        }
 
         internal static bool CurrentThreadSubscriptionsAllowed => current_thread_subscriptions_allowed.Value;
 
@@ -506,6 +505,8 @@ namespace osu.Game.Database
             if (isDisposed)
                 throw new ObjectDisposedException(nameof(RealmContextFactory));
 
+            SynchronizationContext syncContext;
+
             try
             {
                 contextCreationLock.Wait();
@@ -515,6 +516,8 @@ namespace osu.Game.Database
                     if (!ThreadSafety.IsUpdateThread && context != null)
                         throw new InvalidOperationException(@$"{nameof(BlockAllOperations)} must be called from the update thread.");
 
+                    syncContext = SynchronizationContext.Current;
+
                     Logger.Log(@"Blocking realm operations.", LoggingTarget.Database);
 
                     context?.Dispose();
@@ -553,6 +556,9 @@ namespace osu.Game.Database
             {
                 factory.contextCreationLock.Release();
                 Logger.Log(@"Restoring realm operations.", LoggingTarget.Database);
+
+                // Post back to the update thread to revive any subscriptions.
+                syncContext?.Post(_ => ensureUpdateContext(), null);
             });
         }
 

osu.Game/Overlays/Settings/Sections/DebugSettings/MemorySettings.cs

@@ -33,10 +33,6 @@ namespace osu.Game.Overlays.Settings.Sections.DebugSettings
                         using (realmFactory.BlockAllOperations())
                         {
                         }
-
-                        // retrieve context to revive realm subscriptions.
-                        // TODO: should we do this from OsuGame or RealmContextFactory or something? Answer: yes.
-                        var _ = realmFactory.Context;
                     }
                 },
             };