From 3ec7dc3bb94972fe16a7359db595faf8136bf5fa Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Sun, 4 Jul 2021 17:59:39 +0900
Subject: [PATCH] Update tests in line with thread safety check

---
 .../Database/TestRealmKeyBindingStore.cs      | 54 +++++++++++--------
 osu.Game/Database/RealmContextFactory.cs      | 21 +++++---
 2 files changed, 47 insertions(+), 28 deletions(-)

diff --git a/osu.Game.Tests/Database/TestRealmKeyBindingStore.cs b/osu.Game.Tests/Database/TestRealmKeyBindingStore.cs
index cac331451b..642ecf00b8 100644
--- a/osu.Game.Tests/Database/TestRealmKeyBindingStore.cs
+++ b/osu.Game.Tests/Database/TestRealmKeyBindingStore.cs
@@ -38,19 +38,28 @@ namespace osu.Game.Tests.Database
         [Test]
         public void TestDefaultsPopulationAndQuery()
         {
-            Assert.That(query().Count, Is.EqualTo(0));
+            Assert.That(queryCount(), Is.EqualTo(0));
 
             KeyBindingContainer testContainer = new TestKeyBindingContainer();
 
             keyBindingStore.Register(testContainer);
 
-            Assert.That(query().Count, Is.EqualTo(3));
+            Assert.That(queryCount(), Is.EqualTo(3));
 
-            Assert.That(query().Where(k => k.ActionInt == (int)GlobalAction.Back).Count, Is.EqualTo(1));
-            Assert.That(query().Where(k => k.ActionInt == (int)GlobalAction.Select).Count, Is.EqualTo(2));
+            Assert.That(queryCount(GlobalAction.Back), Is.EqualTo(1));
+            Assert.That(queryCount(GlobalAction.Select), Is.EqualTo(2));
         }
 
-        private IQueryable<RealmKeyBinding> query() => realmContextFactory.Context.All<RealmKeyBinding>();
+        private int queryCount(GlobalAction? match = null)
+        {
+            using (var usage = realmContextFactory.GetForRead())
+            {
+                var results = usage.Realm.All<RealmKeyBinding>();
+                if (match.HasValue)
+                    results = results.Where(k => k.ActionInt == (int)match.Value);
+                return results.Count();
+            }
+        }
 
         [Test]
         public void TestUpdateViaQueriedReference()
@@ -59,25 +68,28 @@ namespace osu.Game.Tests.Database
 
             keyBindingStore.Register(testContainer);
 
-            var backBinding = query().Single(k => k.ActionInt == (int)GlobalAction.Back);
-
-            Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.Escape }));
-
-            var tsr = ThreadSafeReference.Create(backBinding);
-
-            using (var usage = realmContextFactory.GetForWrite())
+            using (var primaryUsage = realmContextFactory.GetForRead())
             {
-                var binding = usage.Realm.ResolveReference(tsr);
-                binding.KeyCombination = new KeyCombination(InputKey.BackSpace);
+                var backBinding = primaryUsage.Realm.All<RealmKeyBinding>().Single(k => k.ActionInt == (int)GlobalAction.Back);
 
-                usage.Commit();
+                Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.Escape }));
+
+                var tsr = ThreadSafeReference.Create(backBinding);
+
+                using (var usage = realmContextFactory.GetForWrite())
+                {
+                    var binding = usage.Realm.ResolveReference(tsr);
+                    binding.KeyCombination = new KeyCombination(InputKey.BackSpace);
+
+                    usage.Commit();
+                }
+
+                Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
+
+                // check still correct after re-query.
+                backBinding = primaryUsage.Realm.All<RealmKeyBinding>().Single(k => k.ActionInt == (int)GlobalAction.Back);
+                Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
             }
-
-            Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
-
-            // check still correct after re-query.
-            backBinding = query().Single(k => k.ActionInt == (int)GlobalAction.Back);
-            Assert.That(backBinding.KeyCombination.Keys, Is.EquivalentTo(new[] { InputKey.BackSpace }));
         }
 
         [TearDown]
diff --git a/osu.Game/Database/RealmContextFactory.cs b/osu.Game/Database/RealmContextFactory.cs
index 3354b97849..f706c37419 100644
--- a/osu.Game/Database/RealmContextFactory.cs
+++ b/osu.Game/Database/RealmContextFactory.cs
@@ -4,6 +4,7 @@
 using System;
 using System.Threading;
 using osu.Framework.Allocation;
+using osu.Framework.Development;
 using osu.Framework.Graphics;
 using osu.Framework.Logging;
 using osu.Framework.Platform;
@@ -46,15 +47,21 @@ namespace osu.Game.Database
         {
             get
             {
-                if (context == null)
+                if (!ThreadSafety.IsUpdateThread)
+                    throw new InvalidOperationException($"Use {nameof(GetForRead)} when performing realm operations from a non-update thread");
+
+                lock (updateContextLock)
                 {
-                    context = createContext();
-                    Logger.Log($"Opened realm \"{context.Config.DatabasePath}\" at version {context.Config.SchemaVersion}");
+                    if (context == null)
+                    {
+                        context = createContext();
+                        Logger.Log($"Opened realm \"{context.Config.DatabasePath}\" at version {context.Config.SchemaVersion}");
+                    }
+
+                    // creating a context will ensure our schema is up-to-date and migrated.
+
+                    return context;
                 }
-
-                // creating a context will ensure our schema is up-to-date and migrated.
-
-                return context;
             }
         }