From b9ec860cf2c7a5a3eae50cc06c6301e7ed5e5802 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 18 Jan 2022 12:20:52 +0900
Subject: [PATCH] Ensure global beatmap/ruleset are always mutated from the
 update thread

This came up while testing the new realm thread, where `MusicController`
would fall over when `OsuTestScene` changes the global beatmap from an
async load thread (causing a cross-thread realm access).

We don't want to have to schedule every usage of these bindables, so
this seems like a good constraint to put in place.
---
 osu.Game/OsuGameBase.cs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/osu.Game/OsuGameBase.cs b/osu.Game/OsuGameBase.cs
index 9256514a0a..8126b74418 100644
--- a/osu.Game/OsuGameBase.cs
+++ b/osu.Game/OsuGameBase.cs
@@ -327,6 +327,7 @@ namespace osu.Game
             dependencies.CacheAs(MusicController);
 
             Ruleset.BindValueChanged(onRulesetChanged);
+            Beatmap.BindValueChanged(onBeatmapChanged);
         }
 
         protected virtual void InitialiseFonts()
@@ -448,8 +449,17 @@ namespace osu.Game
 
         protected override Storage CreateStorage(GameHost host, Storage defaultStorage) => new OsuStorage(host, defaultStorage);
 
+        private void onBeatmapChanged(ValueChangedEvent<WorkingBeatmap> valueChangedEvent)
+        {
+            if (!ThreadSafety.IsUpdateThread)
+                throw new InvalidOperationException("Global beatmap bindable must be changed from update thread.");
+        }
+
         private void onRulesetChanged(ValueChangedEvent<RulesetInfo> r)
         {
+            if (!ThreadSafety.IsUpdateThread)
+                throw new InvalidOperationException("Global ruleset bindable must be changed from update thread.");
+
             if (r.NewValue?.Available != true)
             {
                 // reject the change if the ruleset is not available.