From a1d60415574b9d12953bd45163aea3b177467557 Mon Sep 17 00:00:00 2001
From: Peter Morris <mrpmorris@gmail.com>
Date: Fri, 9 Dec 2022 12:52:21 +0000
Subject: [PATCH] Fix memory leak when using ActionSubscriber or
 SubscribeToAction (Fixes #378) (#380)

Fix memory leak when using ActionSubscriber or SubscribeToAction (Fixes #378)
---
 Docs/releases.md                      |  3 +++
 Source/Lib/Fluxor/ActionSubscriber.cs | 18 ++++++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/Docs/releases.md b/Docs/releases.md
index 0e96380c..c419d281 100644
--- a/Docs/releases.md
+++ b/Docs/releases.md
@@ -1,5 +1,8 @@
 # Releases
 
+## New in 5.7
+* Fixes memory leak when using `ActionSubscriber` or `SubscribeToAction` ([#378](https://github.com/mrpmorris/Fluxor/issues/378))
+
 ## New in 5.6
 * Support .NET 7
 * Ensure StateSelection unsubscribes properly ([#353](https://github.com/mrpmorris/Fluxor/issues/353))
diff --git a/Source/Lib/Fluxor/ActionSubscriber.cs b/Source/Lib/Fluxor/ActionSubscriber.cs
index ec4953af..4768e590 100644
--- a/Source/Lib/Fluxor/ActionSubscriber.cs
+++ b/Source/Lib/Fluxor/ActionSubscriber.cs
@@ -1,8 +1,6 @@
-using Fluxor.Extensions;
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Threading;
 
 namespace Fluxor
 {
@@ -23,7 +21,7 @@ public void Notify(object action)
 			if (action is null)
 				throw new ArgumentNullException(nameof(action));
 
-			lock(SyncRoot)
+			lock (SyncRoot)
 			{
 				IEnumerable<Action<object>> callbacks =
 					SubscriptionsForType
@@ -48,7 +46,7 @@ public void SubscribeToAction<TAction>(object subscriber, Action<TAction> callba
 				actionType: typeof(TAction),
 				callback: (object action) => callback((TAction)action));
 
-			lock(SyncRoot)
+			lock (SyncRoot)
 			{
 				if (!SubscriptionsForInstance.TryGetValue(subscriber, out List<ActionSubscription> instanceSubscriptions))
 				{
@@ -72,17 +70,22 @@ public void UnsubscribeFromAllActions(object subscriber)
 				throw new ArgumentNullException(nameof(subscriber));
 
 			List<ActionSubscription> instanceSubscriptions;
-			lock(SyncRoot)
+			lock (SyncRoot)
 			{
 				if (!SubscriptionsForInstance.TryGetValue(subscriber, out instanceSubscriptions))
 					return;
 
+				IEnumerable<object> subscribedInstances =
+					instanceSubscriptions
+						.Select(x => x.Subscriber)
+						.Distinct();
+
 				IEnumerable<Type> subscribedActionTypes =
 					instanceSubscriptions
 						.Select(x => x.ActionType)
 						.Distinct();
 
-				foreach(Type actionType in subscribedActionTypes)
+				foreach (Type actionType in subscribedActionTypes)
 				{
 					List<ActionSubscription> actionTypeSubscriptions;
 					if (!SubscriptionsForType.TryGetValue(actionType, out actionTypeSubscriptions))
@@ -91,6 +94,9 @@ public void UnsubscribeFromAllActions(object subscriber)
 						.Except(instanceSubscriptions)
 						.ToList();
 				}
+
+				foreach (object subscription in subscribedInstances)
+					SubscriptionsForInstance.Remove(subscription);
 			}
 		}
 	}