Address gdk's comments

Ryujinx.HLE/FileSystem/SaveHelper.cs

@@ -32,7 +32,7 @@ namespace Ryujinx.HLE.FileSystem
                 currentTitleId = context.Process.TitleId;
             }
 
-            string saveAccount = saveMetaData.UserId.IsZero() ? "savecommon" : saveMetaData.UserId.ToString();
+            string saveAccount = saveMetaData.UserId.IsNull ? "savecommon" : saveMetaData.UserId.ToString();
 
             string savePath = Path.Combine(baseSavePath,
                 saveMetaData.SaveId.ToString("x16"),

Ryujinx.HLE/HOS/Services/Friend/FriendServicePermissionLevel.cs

@@ -3,20 +3,17 @@
 namespace Ryujinx.HLE.HOS.Services.Friend
 {
     [Flags]
-    enum FriendServicePermissionLevelMask
-    {
-        User    = 1,
-        Overlay = 2,
-        Manager = 4,
-        System  = 8
-    }
-
     enum FriendServicePermissionLevel
     {
+        UserMask    = 1,
+        OverlayMask = 2,
+        ManagerMask = 4,
+        SystemMask  = 8,
+
         Admin   = -1,
-        User    = FriendServicePermissionLevelMask.User,
+        User    = UserMask,
-        Overlay = FriendServicePermissionLevelMask.User | FriendServicePermissionLevelMask.Overlay,
+        Overlay = UserMask | OverlayMask,
-        Manager = FriendServicePermissionLevelMask.User | FriendServicePermissionLevelMask.Overlay | FriendServicePermissionLevelMask.Manager,
+        Manager = UserMask | OverlayMask | ManagerMask,
-        System  = FriendServicePermissionLevelMask.User | FriendServicePermissionLevelMask.System
+        System  = UserMask | SystemMask
     }
 }

Ryujinx.HLE/HOS/Services/Friend/INotificationService.cs

@@ -22,8 +22,9 @@ namespace Ryujinx.HLE.HOS.Services.Friend
 
 
         private LinkedList<NotificationInfo> _notifications;
-        private bool                         _hasNewFriendRequest;
+
-        private bool                         _hasFriendListUpdate;
+        private bool _hasNewFriendRequest;
+        private bool _hasFriendListUpdate;
 
         private Dictionary<int, ServiceProcessRequest> _commands;
 
@@ -111,7 +112,7 @@ namespace Ryujinx.HLE.HOS.Services.Friend
         {
             lock (_lock)
             {
-                if (_userId.Equals(targetId))
+                if (_userId == targetId)
                 {
                     if (!_hasFriendListUpdate)
                     {
@@ -153,7 +154,7 @@ namespace Ryujinx.HLE.HOS.Services.Friend
         {
             lock (_lock)
             {
-                if (((int)_permissionLevel & (int)FriendServicePermissionLevelMask.Overlay) != 0 && _userId.Equals(targetId))
+                if ((_permissionLevel & FriendServicePermissionLevel.OverlayMask) != 0 && _userId == targetId)
                 {
                     if (!_hasNewFriendRequest)
                     {
@@ -178,15 +179,7 @@ namespace Ryujinx.HLE.HOS.Services.Friend
 
         public void Dispose()
         {
-            Dispose(true);
+            NotificationEventHandler.Instance.UnregisterNotificationService(this);
-        }
-
-        protected virtual void Dispose(bool disposing)
-        {
-            if (disposing)
-            {
-                NotificationEventHandler.Instance.UnregisterNotificationService(this);
-            }
         }
     }
 }

Ryujinx.HLE/HOS/Services/Friend/NotificationEventHandler.cs

@@ -9,6 +9,22 @@ namespace Ryujinx.HLE.HOS.Services.Friend
 
         private INotificationService[] _registry;
 
+        public static NotificationEventHandler Instance
+        {
+            get
+            {
+                lock (instanceLock)
+                {
+                    if (instance == null)
+                    {
+                        instance = new NotificationEventHandler();
+                    }
+
+                    return instance;
+                }
+            }
+        }
+
         NotificationEventHandler()
         {
             _registry = new INotificationService[0x20];
@@ -63,21 +79,5 @@ namespace Ryujinx.HLE.HOS.Services.Friend
                 }
             }
         }
-
-        public static NotificationEventHandler Instance
-        {
-            get
-            {
-                lock (instanceLock)
-                {
-                    if (instance == null)
-                    {
-                        instance = new NotificationEventHandler();
-                    }
-
-                    return instance;
-                }
-            }
-        }
     }
 }

Ryujinx.HLE/Utilities/UInt128.cs

@@ -6,10 +6,10 @@ using System.Runtime.InteropServices;
 namespace Ryujinx.HLE.Utilities
 {
     [StructLayout(LayoutKind.Sequential)]
-    public struct UInt128
+    public struct UInt128 : IEquatable<UInt128>
     {
-        public long Low  { get; private set; }
+        public readonly long Low;
-        public long High { get; private set; }
+        public readonly long High;
 
         public bool IsNull => (Low | High) == 0;
 
@@ -47,14 +47,29 @@ namespace Ryujinx.HLE.Utilities
             return High.ToString("x16") + Low.ToString("x16");
         }
 
-        public bool IsZero()
+        public static bool operator ==(UInt128 x, UInt128 y)
         {
-            return (Low | High) == 0;
+            return x.Equals(y);
+        }
+
+        public static bool operator !=(UInt128 x, UInt128 y)
+        {
+            return !x.Equals(y);
+        }
+
+        public override bool Equals(object obj)
+        {
+            return obj is UInt128 uint128 && Equals(uint128);
         }
 
         public bool Equals(UInt128 cmpObj)
         {
             return Low == cmpObj.Low && High == cmpObj.High;
         }
+
+        public override int GetHashCode()
+        {
+            return HashCode.Combine(Low, High);
+        }
     }
 }