From cad048def3025c72c6c9a940e82eb335bf9a7b4f Mon Sep 17 00:00:00 2001
From: Enderlook <enderlook@gmail.com>
Date: Tue, 12 Apr 2022 18:08:20 -0300
Subject: [PATCH] Fix callbacks that listen to derived event types not being
 raised unless the derived type has at least one subscribed callback

Implementation for GH-1.
---
 CHANGELOG.md                                  |  4 +++
 .../Enderlook.EventManager.csproj             |  2 +-
 Enderlook.EventManager/src/EventManager.cs    | 30 +++++++++++--------
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7e81665..ed249e8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.4.1
+
+- Fix callbacks that listen to derived event types not being raised unless the derived type has at least one subscribed callback.
+
 ## 0.4.0
 
 - Increase performance on weak handles.
diff --git a/Enderlook.EventManager/Enderlook.EventManager.csproj b/Enderlook.EventManager/Enderlook.EventManager.csproj
index 4659647..ee54fd4 100644
--- a/Enderlook.EventManager/Enderlook.EventManager.csproj
+++ b/Enderlook.EventManager/Enderlook.EventManager.csproj
@@ -10,7 +10,7 @@
     <Product>Enderlook.EventManager</Product>
     <RepositoryUrl>https://github.com/Enderlook/Net-Event-Manager</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
-    <Version>0.4.0</Version>
+    <Version>0.4.1</Version>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
     <LangVersion>10</LangVersion>
diff --git a/Enderlook.EventManager/src/EventManager.cs b/Enderlook.EventManager/src/EventManager.cs
index f7b961c..dbda1ca 100644
--- a/Enderlook.EventManager/src/EventManager.cs
+++ b/Enderlook.EventManager/src/EventManager.cs
@@ -54,8 +54,11 @@ public void Raise<TEvent>(TEvent argument)
                 manager_.StaticRaise(argument, this);
             }
             else
-                ReadEnd();
+                SlowPath();
         }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        void SlowPath() => CreateInvokersHolderManager<TEvent>().StaticRaise(argument, this);
     }
 
     /// <summary>
@@ -76,8 +79,11 @@ public void Raise<TEvent>(TEvent argument)
                 manager_.StaticRaise(new TEvent(), this);
             }
             else
-                ReadEnd();
+                SlowPath();
         }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        void SlowPath() => CreateInvokersHolderManager<TEvent>().StaticRaise(new TEvent(), this);
     }
 
     /// <summary>
@@ -97,9 +103,10 @@ public void Raise<TEvent>(TEvent argument)
     /// <exception cref="ObjectDisposedException">Thrown when this instance has already been disposed.</exception>
     public void DynamicRaise<TEvent>(TEvent argument)
     {
+        Type key = argument?.GetType() ?? typeof(TEvent);
         ReadBegin();
         {
-            if (managersPerType.TryGetValue(argument?.GetType() ?? typeof(TEvent), out InvokersHolderManager? manager))
+            if (managersPerType.TryGetValue(key, out InvokersHolderManager? manager))
             {
                 FromReadToInHolder();
                 // TODO: This virtual call is actually only required if argument.GetType().IsValueType
@@ -107,8 +114,11 @@ public void DynamicRaise<TEvent>(TEvent argument)
                 manager.DynamicRaise(argument, this);
             }
             else
-                ReadEnd();
+                SlowPath();
         }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        void SlowPath() => CreateInvokersHolderManagerDynamic(key).DynamicRaise(argument, this);
     }
 
     internal void Unsubscribe<TEvent, TCallbackHelper, TPredicator, TCallback>(TPredicator predicator, bool listenToAssignableEvents)
@@ -254,15 +264,12 @@ private InvokersHolderManager CreateInvokersHolderManagerDynamic(Type type)
     }
 
     [MethodImpl(MethodImplOptions.NoInlining)]
-    private InvokersHolderManager CreateInvokersHolderManager<TEvent>()
+    private InvokersHolderManager<TEvent> CreateInvokersHolderManager<TEvent>()
     {
         InvokersHolderManager? manager;
         FromReadToWrite();
         {
-            ref InvokersHolderManager slot = ref managersPerType.GetOrCreateValueSlot(typeof(TEvent), out bool found);
-            if (found)
-                manager = slot;
-            else
+            if (!managersPerType.TryGetValue(typeof(TEvent), out manager))
             {
                 manager = new InvokersHolderManager<TEvent>();
 
@@ -278,12 +285,11 @@ private InvokersHolderManager CreateInvokersHolderManager<TEvent>()
                         }
                     }
                 }
-
-                slot = manager;
+                managersPerType.Add(typeof(TEvent), manager);
             }
         }
         FromWriteToInHolder();
-        return manager;
+        return Utils.ExpectExactType<InvokersHolderManager<TEvent>>(manager);
     }
 
     [DoesNotReturn]