Reworked event system, fixed presence and voice state updates

src/Discord.Net/API/DiscordAPIClient.cs

@@ -1,6 +1,5 @@
 using Discord.API.Gateway;
 using Discord.API.Rest;
-using Discord.Extensions;
 using Discord.Net;
 using Discord.Net.Converters;
 using Discord.Net.Queue;
@@ -24,10 +23,17 @@ namespace Discord.API
 {
     public class DiscordApiClient : IDisposable
     {
-        public event Func<string, string, double, Task> SentRequest;
-        public event Func<int, Task> SentGatewayMessage;
-        public event Func<GatewayOpCode, int?, string, object, Task> ReceivedGatewayEvent;
-        public event Func<Exception, Task> Disconnected;
+        private object _eventLock = new object();
+
+        public event Func<string, string, double, Task> SentRequest { add { _sentRequestEvent.Add(value); } remove { _sentRequestEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<string, string, double, Task>> _sentRequestEvent = new AsyncEvent<Func<string, string, double, Task>>();
+        public event Func<int, Task> SentGatewayMessage { add { _sentGatewayMessageEvent.Add(value); } remove { _sentGatewayMessageEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<int, Task>> _sentGatewayMessageEvent = new AsyncEvent<Func<int, Task>>();
+
+        public event Func<GatewayOpCode, int?, string, object, Task> ReceivedGatewayEvent { add { _receivedGatewayEvent.Add(value); } remove { _receivedGatewayEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<GatewayOpCode, int?, string, object, Task>> _receivedGatewayEvent = new AsyncEvent<Func<GatewayOpCode, int?, string, object, Task>>();
+        public event Func<Exception, Task> Disconnected { add { _disconnectedEvent.Add(value); } remove { _disconnectedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Exception, Task>> _disconnectedEvent = new AsyncEvent<Func<Exception, Task>>();
 
         private readonly RequestQueue _requestQueue;
         private readonly JsonSerializer _serializer;
@@ -67,19 +73,19 @@ namespace Discord.API
                         using (var reader = new StreamReader(decompressed))
                         {
                             var msg = JsonConvert.DeserializeObject<WebSocketMessage>(reader.ReadToEnd());
-                            await ReceivedGatewayEvent.RaiseAsync((GatewayOpCode)msg.Operation, msg.Sequence, msg.Type, msg.Payload).ConfigureAwait(false);
+                            await _receivedGatewayEvent.InvokeAsync((GatewayOpCode)msg.Operation, msg.Sequence, msg.Type, msg.Payload).ConfigureAwait(false);
                         }
                     }
                 };
                 _gatewayClient.TextMessage += async text =>
                 {
                     var msg = JsonConvert.DeserializeObject<WebSocketMessage>(text);
-                    await ReceivedGatewayEvent.RaiseAsync((GatewayOpCode)msg.Operation, msg.Sequence, msg.Type, msg.Payload).ConfigureAwait(false);
+                    await _receivedGatewayEvent.InvokeAsync((GatewayOpCode)msg.Operation, msg.Sequence, msg.Type, msg.Payload).ConfigureAwait(false);
                 };
                 _gatewayClient.Closed += async ex =>
                 {
                     await DisconnectAsync().ConfigureAwait(false);
-                    await Disconnected.RaiseAsync(ex).ConfigureAwait(false);
+                    await _disconnectedEvent.InvokeAsync(ex).ConfigureAwait(false);
                 };
             }
 
@@ -311,7 +317,7 @@ namespace Discord.API
             stopwatch.Stop();
 
             double milliseconds = ToMilliseconds(stopwatch);
-            await SentRequest.RaiseAsync(method, endpoint, milliseconds).ConfigureAwait(false);
+            await _sentRequestEvent.InvokeAsync(method, endpoint, milliseconds).ConfigureAwait(false);
 
             return responseStream;
         }
@@ -324,7 +330,7 @@ namespace Discord.API
             stopwatch.Stop();
 
             double milliseconds = ToMilliseconds(stopwatch);
-            await SentRequest.RaiseAsync(method, endpoint, milliseconds).ConfigureAwait(false);
+            await _sentRequestEvent.InvokeAsync(method, endpoint, milliseconds).ConfigureAwait(false);
 
             return responseStream;
         }
@@ -344,7 +350,7 @@ namespace Discord.API
             if (payload != null)
                 bytes = Encoding.UTF8.GetBytes(SerializeJson(payload));
             await _requestQueue.SendAsync(new WebSocketRequest(_gatewayClient, bytes, true, options), group, bucketId, guildId).ConfigureAwait(false);
-            await SentGatewayMessage.RaiseAsync((int)opCode).ConfigureAwait(false);
+            await _sentGatewayMessageEvent.InvokeAsync((int)opCode).ConfigureAwait(false);
         }
 
         //Auth

src/Discord.Net/DiscordClient.cs

@@ -15,8 +15,15 @@ namespace Discord
 {
     public class DiscordClient : IDiscordClient
     {
-        public event Func<LogMessage, Task> Log;
-        public event Func<Task> LoggedIn, LoggedOut;
+        private readonly object _eventLock = new object();
+
+        public event Func<LogMessage, Task> Log { add { _logEvent.Add(value); } remove { _logEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<LogMessage, Task>> _logEvent = new AsyncEvent<Func<LogMessage, Task>>();
+
+        public event Func<Task> LoggedIn { add { _loggedInEvent.Add(value); } remove { _loggedInEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Task>> _loggedInEvent = new AsyncEvent<Func<Task>>();
+        public event Func<Task> LoggedOut { add { _loggedOutEvent.Add(value); } remove { _loggedOutEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Task>> _loggedOutEvent = new AsyncEvent<Func<Task>>();
 
         internal readonly Logger _discordLogger, _restLogger, _queueLogger;
         internal readonly SemaphoreSlim _connectionLock;
@@ -35,7 +42,7 @@ namespace Discord
         public DiscordClient(DiscordConfig config)
         {
             _log = new LogManager(config.LogLevel);
-            _log.Message += async msg => await Log.RaiseAsync(msg).ConfigureAwait(false);
+            _log.Message += async msg => await _logEvent.InvokeAsync(msg).ConfigureAwait(false);
             _discordLogger = _log.CreateLogger("Discord");
             _restLogger = _log.CreateLogger("Rest");
             _queueLogger = _log.CreateLogger("Queue");
@@ -96,7 +103,7 @@ namespace Discord
                 throw;
             }
 
-            await LoggedIn.RaiseAsync().ConfigureAwait(false);
+            await _loggedInEvent.InvokeAsync().ConfigureAwait(false);
         }
         protected virtual Task OnLoginAsync() => Task.CompletedTask;
 
@@ -123,7 +130,7 @@ namespace Discord
 
             LoginState = LoginState.LoggedOut;
 
-            await LoggedOut.RaiseAsync().ConfigureAwait(false);
+            await _loggedOutEvent.InvokeAsync().ConfigureAwait(false);
         }
         protected virtual Task OnLogoutAsync() => Task.CompletedTask;
 

src/Discord.Net/DiscordSocketClient.cs

@@ -21,22 +21,74 @@ namespace Discord
     //TODO: Add resume logic
     public class DiscordSocketClient : DiscordClient, IDiscordClient
     {
-        public event Func<Task> Connected, Disconnected, Ready;
-        //public event Func<Channel> VoiceConnected, VoiceDisconnected;
-        public event Func<IChannel, Task> ChannelCreated, ChannelDestroyed;
-        public event Func<IChannel, IChannel, Task> ChannelUpdated;
-        public event Func<IMessage, Task> MessageReceived, MessageDeleted;
-        public event Func<IMessage, IMessage, Task> MessageUpdated;
-        public event Func<IRole, Task> RoleCreated, RoleDeleted;
-        public event Func<IRole, IRole, Task> RoleUpdated;
-        public event Func<IGuild, Task> JoinedGuild, LeftGuild, GuildAvailable, GuildUnavailable, GuildDownloadedMembers;
-        public event Func<IGuild, IGuild, Task> GuildUpdated;
-        public event Func<IUser, Task> UserJoined, UserLeft, UserBanned, UserUnbanned;
-        public event Func<IUser, IUser, Task> UserUpdated;
-        public event Func<ISelfUser, ISelfUser, Task> CurrentUserUpdated;
-        public event Func<IChannel, IUser, Task> UserIsTyping;
-        public event Func<int, Task> LatencyUpdated;
-        //TODO: Add PresenceUpdated? VoiceStateUpdated?
+        private object _eventLock = new object();
+
+        //General
+        public event Func<Task> Connected { add { _connectedEvent.Add(value); } remove { _connectedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Task>> _connectedEvent = new AsyncEvent<Func<Task>>();
+        public event Func<Task> Disconnected { add { _disconnectedEvent.Add(value); } remove { _disconnectedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Task>> _disconnectedEvent = new AsyncEvent<Func<Task>>();
+        public event Func<Task> Ready { add { _readyEvent.Add(value); } remove { _readyEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Task>> _readyEvent = new AsyncEvent<Func<Task>>();
+
+        public event Func<int, int, Task> LatencyUpdated { add { _latencyUpdatedEvent.Add(value); } remove { _latencyUpdatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<int, int, Task>> _latencyUpdatedEvent = new AsyncEvent<Func<int, int, Task>>();
+
+        //Channels
+        public event Func<IChannel, Task> ChannelCreated { add { _channelCreatedEvent.Add(value); } remove { _channelCreatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IChannel, Task>> _channelCreatedEvent = new AsyncEvent<Func<IChannel, Task>>();
+        public event Func<IChannel, Task> ChannelDestroyed { add { _channelDestroyedEvent.Add(value); } remove { _channelDestroyedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IChannel, Task>> _channelDestroyedEvent = new AsyncEvent<Func<IChannel, Task>>();
+        public event Func<IChannel, IChannel, Task> ChannelUpdated { add { _channelUpdatedEvent.Add(value); } remove { _channelUpdatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IChannel, IChannel, Task>> _channelUpdatedEvent = new AsyncEvent<Func<IChannel, IChannel, Task>>();
+
+        //Messages
+        public event Func<IMessage, Task> MessageReceived { add { _messageReceivedEvent.Add(value); } remove { _messageReceivedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IMessage, Task>> _messageReceivedEvent = new AsyncEvent<Func<IMessage, Task>>();
+        public event Func<ulong, Optional<IMessage>, Task> MessageDeleted { add { _messageDeletedEvent.Add(value); } remove { _messageDeletedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<ulong, Optional<IMessage>, Task>> _messageDeletedEvent = new AsyncEvent<Func<ulong, Optional<IMessage>, Task>>();
+        public event Func<Optional<IMessage>, IMessage, Task> MessageUpdated { add { _messageUpdatedEvent.Add(value); } remove { _messageUpdatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Optional<IMessage>, IMessage, Task>> _messageUpdatedEvent = new AsyncEvent<Func<Optional<IMessage>, IMessage, Task>>();
+
+        //Roles
+        public event Func<IRole, Task> RoleCreated { add { _roleCreatedEvent.Add(value); } remove { _roleCreatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IRole, Task>> _roleCreatedEvent = new AsyncEvent<Func<IRole, Task>>();
+        public event Func<IRole, Task> RoleDeleted { add { _roleDeletedEvent.Add(value); } remove { _roleDeletedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IRole, Task>> _roleDeletedEvent = new AsyncEvent<Func<IRole, Task>>();
+        public event Func<IRole, IRole, Task> RoleUpdated { add { _roleUpdatedEvent.Add(value); } remove { _roleUpdatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IRole, IRole, Task>> _roleUpdatedEvent = new AsyncEvent<Func<IRole, IRole, Task>>();
+
+        //Guilds
+        public event Func<IGuild, Task> JoinedGuild { add { _joinedGuildEvent.Add(value); } remove { _joinedGuildEvent.Remove(value); } }
+        private AsyncEvent<Func<IGuild, Task>> _joinedGuildEvent = new AsyncEvent<Func<IGuild, Task>>();
+        public event Func<IGuild, Task> LeftGuild { add { _leftGuildEvent.Add(value); } remove { _leftGuildEvent.Remove(value); } }
+        private AsyncEvent<Func<IGuild, Task>> _leftGuildEvent = new AsyncEvent<Func<IGuild, Task>>();
+        public event Func<IGuild, Task> GuildAvailable { add { _guildAvailableEvent.Add(value); } remove { _guildAvailableEvent.Remove(value); } }
+        private AsyncEvent<Func<IGuild, Task>> _guildAvailableEvent = new AsyncEvent<Func<IGuild, Task>>();
+        public event Func<IGuild, Task> GuildUnavailable { add { _guildUnavailableEvent.Add(value); } remove { _guildUnavailableEvent.Remove(value); } }
+        private AsyncEvent<Func<IGuild, Task>> _guildUnavailableEvent = new AsyncEvent<Func<IGuild, Task>>();
+        public event Func<IGuild, Task> GuildDownloadedMembers { add { _guildDownloadedMembersEvent.Add(value); } remove { _guildDownloadedMembersEvent.Remove(value); } }
+        private AsyncEvent<Func<IGuild, Task>> _guildDownloadedMembersEvent = new AsyncEvent<Func<IGuild, Task>>();
+        public event Func<IGuild, IGuild, Task> GuildUpdated { add { _guildUpdatedEvent.Add(value); } remove { _guildUpdatedEvent.Remove(value); } }
+        private AsyncEvent<Func<IGuild, IGuild, Task>> _guildUpdatedEvent = new AsyncEvent<Func<IGuild, IGuild, Task>>();
+
+        //Users
+        public event Func<IGuildUser, Task> UserJoined { add { _userJoinedEvent.Add(value); } remove { _userJoinedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IGuildUser, Task>> _userJoinedEvent = new AsyncEvent<Func<IGuildUser, Task>>();
+        public event Func<IGuildUser, Task> UserLeft { add { _userLeftEvent.Add(value); } remove { _userLeftEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IGuildUser, Task>> _userLeftEvent = new AsyncEvent<Func<IGuildUser, Task>>();
+        public event Func<IUser, IGuild, Task> UserBanned { add { _userBannedEvent.Add(value); } remove { _userBannedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IUser, IGuild, Task>> _userBannedEvent = new AsyncEvent<Func<IUser, IGuild, Task>>();
+        public event Func<IUser, IGuild, Task> UserUnbanned { add { _userUnbannedEvent.Add(value); } remove { _userUnbannedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IUser, IGuild, Task>> _userUnbannedEvent = new AsyncEvent<Func<IUser, IGuild, Task>>();
+        public event Func<Optional<IGuildUser>, IGuildUser, Task> UserUpdated { add { _userUpdatedEvent.Add(value); } remove { _userUpdatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<Optional<IGuildUser>, IGuildUser, Task>> _userUpdatedEvent = new AsyncEvent<Func<Optional<IGuildUser>, IGuildUser, Task>>();
+        public event Func<ISelfUser, ISelfUser, Task> CurrentUserUpdated { add { _selfUpdatedEvent.Add(value); } remove { _selfUpdatedEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<ISelfUser, ISelfUser, Task>> _selfUpdatedEvent = new AsyncEvent<Func<ISelfUser, ISelfUser, Task>>();
+        public event Func<IUser, IChannel, Task> UserIsTyping { add { _userIsTypingEvent.Add(value); } remove { _userIsTypingEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<IUser, IChannel, Task>> _userIsTypingEvent = new AsyncEvent<Func<IUser, IChannel, Task>>();
+
+        //TODO: Add PresenceUpdated? VoiceStateUpdated?, VoiceConnected, VoiceDisconnected;
 
         private readonly ConcurrentQueue<ulong> _largeGuilds;
         private readonly Logger _gatewayLogger;
@@ -46,7 +98,6 @@ namespace Discord
         private readonly DataStoreProvider _dataStoreProvider;
         private readonly JsonSerializer _serializer;
         private readonly int _connectionTimeout, _reconnectDelay, _failedReconnectDelay;
-        private readonly bool _enablePreUpdateEvents;
         private readonly int _largeThreshold;
         private readonly int _totalShards;
 
@@ -78,8 +129,7 @@ namespace Discord
         internal IReadOnlyCollection<VoiceRegion> VoiceRegions => _voiceRegions.ToReadOnlyCollection();
 
         /// <summary> Creates a new REST/WebSocket discord client. </summary>
-        public DiscordSocketClient()
-            : this(new DiscordSocketConfig()) { }
+        public DiscordSocketClient() : this(new DiscordSocketConfig()) { }
         /// <summary> Creates a new REST/WebSocket discord client. </summary>
         public DiscordSocketClient(DiscordSocketConfig config)
             : base(config)
@@ -93,7 +143,6 @@ namespace Discord
             _dataStoreProvider = config.DataStoreProvider;
 
             MessageCacheSize = config.MessageCacheSize;
-            _enablePreUpdateEvents = config.EnablePreUpdateEvents;
             _largeThreshold = config.LargeThreshold;
             
             _gatewayLogger = _log.CreateLogger("Gateway");
@@ -173,7 +222,7 @@ namespace Discord
                 _connectTask = new TaskCompletionSource<bool>();
                 _cancelToken = new CancellationTokenSource();
                 await ApiClient.ConnectAsync().ConfigureAwait(false);
-                await Connected.RaiseAsync().ConfigureAwait(false);
+                await _connectedEvent.InvokeAsync().ConfigureAwait(false);
 
                 await _connectTask.Task.ConfigureAwait(false);
                 
@@ -228,7 +277,7 @@ namespace Discord
             ConnectionState = ConnectionState.Disconnected;
             await _gatewayLogger.InfoAsync("Disconnected").ConfigureAwait(false);
 
-            await Disconnected.RaiseAsync().ConfigureAwait(false);
+            await _disconnectedEvent.InvokeAsync().ConfigureAwait(false);
         }
         private async Task StartReconnectAsync()
         {
@@ -463,12 +512,14 @@ namespace Discord
                             var heartbeatTime = _heartbeatTime;
                             if (heartbeatTime != 0)
                             {
-                                var latency = (int)(Environment.TickCount - _heartbeatTime);
+                                int latency = (int)(Environment.TickCount - _heartbeatTime);
                                 _heartbeatTime = 0;
                                 await _gatewayLogger.VerboseAsync($"Latency = {latency} ms").ConfigureAwait(false);
+
+                                int before = Latency;
                                 Latency = latency;
 
-                                await LatencyUpdated.RaiseAsync(latency).ConfigureAwait(false);
+                                await _latencyUpdatedEvent.InvokeAsync(before, latency).ConfigureAwait(false);
                             }
                         }
                         break;
@@ -523,7 +574,7 @@ namespace Discord
 
                                     _guildDownloadTask = WaitForGuildsAsync(_cancelToken.Token);
 
-                                    await Ready.RaiseAsync().ConfigureAwait(false);
+                                    await _readyEvent.InvokeAsync().ConfigureAwait(false);
 
                                     _connectTask.TrySetResult(true); //Signal the .Connect() call to complete
                                     await _gatewayLogger.InfoAsync("Ready").ConfigureAwait(false);
@@ -546,7 +597,7 @@ namespace Discord
                                     if (data.Unavailable != false)
                                     {
                                         guild = AddGuild(data, DataStore);
-                                        await JoinedGuild.RaiseAsync(guild).ConfigureAwait(false);
+                                        await _joinedGuildEvent.InvokeAsync(guild).ConfigureAwait(false);
                                         await _gatewayLogger.InfoAsync($"Joined {data.Name}").ConfigureAwait(false);
                                     }
                                     else
@@ -568,7 +619,7 @@ namespace Discord
                                     if (data.Unavailable != true)
                                     {
                                         await _gatewayLogger.VerboseAsync($"Connected to {data.Name}").ConfigureAwait(false);
-                                        await GuildAvailable.RaiseAsync(guild).ConfigureAwait(false);
+                                        await _guildAvailableEvent.InvokeAsync(guild).ConfigureAwait(false);
                                     }
                                 }
                                 break;
@@ -580,9 +631,9 @@ namespace Discord
                                     var guild = DataStore.GetGuild(data.Id);
                                     if (guild != null)
                                     {
-                                        var before = _enablePreUpdateEvents ? guild.Clone() : null;
+                                        var before = guild.Clone();
                                         guild.Update(data, UpdateSource.WebSocket);
-                                        await GuildUpdated.RaiseAsync(before, guild).ConfigureAwait(false);
+                                        await _guildUpdatedEvent.InvokeAsync(before, guild).ConfigureAwait(false);
                                     }
                                     else
                                     {
@@ -604,11 +655,11 @@ namespace Discord
                                         foreach (var member in guild.Members)
                                             member.User.RemoveRef(this);
 
-                                        await GuildUnavailable.RaiseAsync(guild).ConfigureAwait(false);
+                                        await _guildUnavailableEvent.InvokeAsync(guild).ConfigureAwait(false);
                                         await _gatewayLogger.VerboseAsync($"Disconnected from {data.Name}").ConfigureAwait(false);
                                         if (data.Unavailable != true)
                                         {
-                                            await LeftGuild.RaiseAsync(guild).ConfigureAwait(false);
+                                            await _leftGuildEvent.InvokeAsync(guild).ConfigureAwait(false);
                                             await _gatewayLogger.InfoAsync($"Left {data.Name}").ConfigureAwait(false);
                                         }
                                         else
@@ -644,7 +695,7 @@ namespace Discord
                                     else
                                         channel = AddDMChannel(data, DataStore);
                                     if (channel != null)
-                                        await ChannelCreated.RaiseAsync(channel).ConfigureAwait(false);
+                                        await _channelCreatedEvent.InvokeAsync(channel).ConfigureAwait(false);
                                 }
                                 break;
                             case "CHANNEL_UPDATE":
@@ -655,9 +706,9 @@ namespace Discord
                                     var channel = DataStore.GetChannel(data.Id);
                                     if (channel != null)
                                     {
-                                        var before = _enablePreUpdateEvents ? channel.Clone() : null;
+                                        var before = channel.Clone();
                                         channel.Update(data, UpdateSource.WebSocket);
-                                        await ChannelUpdated.RaiseAsync(before, channel).ConfigureAwait(false);
+                                        await _channelUpdatedEvent.InvokeAsync(before, channel).ConfigureAwait(false);
                                     }
                                     else
                                     {
@@ -686,7 +737,7 @@ namespace Discord
                                     else
                                         channel = RemoveDMChannel(data.Recipient.Value.Id);
                                     if (channel != null)
-                                        await ChannelDestroyed.RaiseAsync(channel).ConfigureAwait(false);
+                                        await _channelDestroyedEvent.InvokeAsync(channel).ConfigureAwait(false);
                                     else
                                     {
                                         await _gatewayLogger.WarningAsync("CHANNEL_DELETE referenced an unknown channel.").ConfigureAwait(false);
@@ -705,7 +756,7 @@ namespace Discord
                                     if (guild != null)
                                     {
                                         var user = guild.AddUser(data, DataStore);
-                                        await UserJoined.RaiseAsync(user).ConfigureAwait(false);
+                                        await _userJoinedEvent.InvokeAsync(user).ConfigureAwait(false);
                                     }
                                     else
                                     {
@@ -725,9 +776,9 @@ namespace Discord
                                         var user = guild.GetUser(data.User.Id);
                                         if (user != null)
                                         {
-                                            var before = _enablePreUpdateEvents ? user.Clone() : null;
+                                            var before = user.Clone();
                                             user.Update(data, UpdateSource.WebSocket);
-                                            await UserUpdated.RaiseAsync(before, user).ConfigureAwait(false);
+                                            await _userUpdatedEvent.InvokeAsync(before, user).ConfigureAwait(false);
                                         }
                                         else
                                         {
@@ -754,7 +805,7 @@ namespace Discord
                                         if (user != null)
                                         {
                                             user.User.RemoveRef(this);
-                                            await UserLeft.RaiseAsync(user).ConfigureAwait(false);
+                                            await _userLeftEvent.InvokeAsync(user).ConfigureAwait(false);
                                         }
                                         else
                                         {
@@ -783,7 +834,7 @@ namespace Discord
                                         if (guild.DownloadedMemberCount >= guild.MemberCount) //Finished downloading for there
                                         {
                                             guild.CompleteDownloadMembers();
-                                            await GuildDownloadedMembers.RaiseAsync(guild).ConfigureAwait(false);
+                                            await _guildDownloadedMembersEvent.InvokeAsync(guild).ConfigureAwait(false);
                                         }
                                     }
                                     else
@@ -804,7 +855,7 @@ namespace Discord
                                     if (guild != null)
                                     {
                                         var role = guild.AddRole(data.Role);
-                                        await RoleCreated.RaiseAsync(role).ConfigureAwait(false);
+                                        await _roleCreatedEvent.InvokeAsync(role).ConfigureAwait(false);
                                     }
                                     else
                                     {
@@ -824,9 +875,9 @@ namespace Discord
                                         var role = guild.GetRole(data.Role.Id);
                                         if (role != null)
                                         {
-                                            var before = _enablePreUpdateEvents ? role.Clone() : null;
+                                            var before = role.Clone();
                                             role.Update(data.Role, UpdateSource.WebSocket);
-                                            await RoleUpdated.RaiseAsync(before, role).ConfigureAwait(false);
+                                            await _roleUpdatedEvent.InvokeAsync(before, role).ConfigureAwait(false);
                                         }
                                         else
                                         {
@@ -851,7 +902,7 @@ namespace Discord
                                     {
                                         var role = guild.RemoveRole(data.RoleId);
                                         if (role != null)
-                                            await RoleDeleted.RaiseAsync(role).ConfigureAwait(false);
+                                            await _roleDeletedEvent.InvokeAsync(role).ConfigureAwait(false);
                                         else
                                         {
                                             await _gatewayLogger.WarningAsync("GUILD_ROLE_DELETE referenced an unknown role.").ConfigureAwait(false);
@@ -874,7 +925,7 @@ namespace Discord
                                     var data = (payload as JToken).ToObject<GuildBanEvent>(_serializer);
                                     var guild = DataStore.GetGuild(data.GuildId);
                                     if (guild != null)
-                                        await UserBanned.RaiseAsync(new User(data.User)).ConfigureAwait(false);
+                                        await _userBannedEvent.InvokeAsync(new User(data.User), guild).ConfigureAwait(false);
                                     else
                                     {
                                         await _gatewayLogger.WarningAsync("GUILD_BAN_ADD referenced an unknown guild.").ConfigureAwait(false);
@@ -889,7 +940,7 @@ namespace Discord
                                     var data = (payload as JToken).ToObject<GuildBanEvent>(_serializer);
                                     var guild = DataStore.GetGuild(data.GuildId);
                                     if (guild != null)
-                                        await UserUnbanned.RaiseAsync(new User(data.User)).ConfigureAwait(false);
+                                        await _userUnbannedEvent.InvokeAsync(new User(data.User), guild).ConfigureAwait(false);
                                     else
                                     {
                                         await _gatewayLogger.WarningAsync("GUILD_BAN_REMOVE referenced an unknown guild.").ConfigureAwait(false);
@@ -912,7 +963,7 @@ namespace Discord
                                         if (author != null)
                                         {
                                             var msg = channel.AddMessage(author, data);
-                                            await MessageReceived.RaiseAsync(msg).ConfigureAwait(false);
+                                            await _messageReceivedEvent.InvokeAsync(msg).ConfigureAwait(false);
                                         }
                                         else
                                         {
@@ -939,7 +990,7 @@ namespace Discord
                                         CachedMessage cachedMsg = channel.GetMessage(data.Id);
                                         if (cachedMsg != null)
                                         {
-                                            before = _enablePreUpdateEvents ? cachedMsg.Clone() : null;
+                                            before = cachedMsg.Clone();
                                             cachedMsg.Update(data, UpdateSource.WebSocket);
                                             after = cachedMsg;
                                         }
@@ -951,7 +1002,12 @@ namespace Discord
                                                 after = new Message(channel, author, data);
                                         }
                                         if (after != null)
-                                            await MessageUpdated.RaiseAsync(before, after).ConfigureAwait(false);
+                                            await _messageUpdatedEvent.InvokeAsync(Optional.Create(before), after).ConfigureAwait(false);
+                                        else
+                                        {
+                                            await _gatewayLogger.WarningAsync("MESSAGE_UPDATE was unable to build an updated message.").ConfigureAwait(false);
+                                            return;
+                                        }
                                     }
                                     else
                                     {
@@ -969,7 +1025,7 @@ namespace Discord
                                     if (channel != null)
                                     {
                                         var msg = channel.RemoveMessage(data.Id);
-                                        await MessageDeleted.RaiseAsync(msg).ConfigureAwait(false);
+                                        await _messageDeletedEvent.InvokeAsync(data.Id, Optional.Create<IMessage>(msg)).ConfigureAwait(false);
                                     }
                                     else
                                     {
@@ -989,7 +1045,7 @@ namespace Discord
                                         foreach (var id in data.Ids)
                                         {
                                             var msg = channel.RemoveMessage(id);
-                                            await MessageDeleted.RaiseAsync(msg).ConfigureAwait(false);
+                                            await _messageDeletedEvent.InvokeAsync(msg.Id, Optional.Create<IMessage>(msg)).ConfigureAwait(false);
                                         }
                                     }
                                     else
@@ -1014,7 +1070,20 @@ namespace Discord
                                             await _gatewayLogger.WarningAsync("PRESENCE_UPDATE referenced an unknown guild.").ConfigureAwait(false);
                                             break;
                                         }
-                                        guild.UpdatePresence(data, DataStore);
+
+                                        var user = guild.GetUser(data.User.Id);
+                                        if (user != null)
+                                        {
+                                            var before = user.Clone();
+                                            user.Update(data, UpdateSource.WebSocket);
+                                            await _userUpdatedEvent.InvokeAsync(before, user).ConfigureAwait(false);
+                                        }
+                                        else
+                                        {
+                                            user = guild.AddOrUpdateUser(data, DataStore);
+                                            user.Update(data, UpdateSource.WebSocket);
+                                            await _userUpdatedEvent.InvokeAsync(Optional.Create<IGuildUser>(), user).ConfigureAwait(false);
+                                        }
                                     }
                                     else
                                     {
@@ -1034,7 +1103,7 @@ namespace Discord
                                     {
                                         var user = channel.GetUser(data.UserId, true);
                                         if (user != null)
-                                            await UserIsTyping.RaiseAsync(channel, user).ConfigureAwait(false);
+                                            await _userIsTypingEvent.InvokeAsync(user, channel).ConfigureAwait(false);
                                     }
                                 }
                                 break;
@@ -1057,7 +1126,11 @@ namespace Discord
 
                                             var user = guild.GetUser(data.UserId);
                                             if (user != null)
+                                            {
+                                                var before =  user.Clone();
                                                 user.Update(data, UpdateSource.WebSocket);
+                                                await _userUpdatedEvent.InvokeAsync(before, user).ConfigureAwait(false);
+                                            }
                                         }
                                         else
                                         {
@@ -1076,9 +1149,9 @@ namespace Discord
                                     var data = (payload as JToken).ToObject<API.User>(_serializer);
                                     if (data.Id == CurrentUser.Id)
                                     {
-                                        var before = _enablePreUpdateEvents ? CurrentUser.Clone() : null;
+                                        var before = CurrentUser.Clone();
                                         CurrentUser.Update(data, UpdateSource.WebSocket);
-                                        await CurrentUserUpdated.RaiseAsync(before, CurrentUser).ConfigureAwait(false);
+                                        await _selfUpdatedEvent.InvokeAsync(before, CurrentUser).ConfigureAwait(false);
                                     }
                                     else
                                     {

src/Discord.Net/DiscordSocketConfig.cs

@@ -24,8 +24,6 @@ namespace Discord
         /// This makes operations such as User.GetPermissions(Channel), User.GuildPermissions, Channel.GetUser, and Channel.Members much faster at the expense of increased memory usage.
         /// </summary>
         public bool UsePermissionsCache { get; set; } = false;*/
-        /// <summary> Gets or sets whether the a copy of a model is generated on an update event to allow you to check which properties changed. </summary>
-        public bool EnablePreUpdateEvents { get; set; } = true;
         /// <summary> 
         /// Gets or sets the max number of users a guild may have for offline users to be included in the READY packet. Max is 250. 
         /// Decreasing this may reduce CPU usage while increasing login time and network usage. 

src/Discord.Net/Entities/WebSocket/CachedGuild.cs

@@ -90,11 +90,7 @@ namespace Discord
                     _downloaderPromise.SetResult(true);
 
                 for (int i = 0; i < model.Presences.Length; i++)
-                {
-                    var presence = model.Presences[i];
-                    UpdatePresence(presence, dataStore, members);
-                    //AddUser(presence, dataStore, members);
-                }
+                    AddOrUpdateUser(model.Presences[i], dataStore, members);
             }
             _members = members;
             
@@ -163,7 +159,7 @@ namespace Discord
             }
             return member;
         }
-        public CachedGuildUser AddUser(PresenceModel model, DataStore dataStore, ConcurrentDictionary<ulong, CachedGuildUser> members = null)
+        public CachedGuildUser AddOrUpdateUser(PresenceModel model, DataStore dataStore, ConcurrentDictionary<ulong, CachedGuildUser> members = null)
         {
             members = members ?? _members;
 
@@ -194,22 +190,6 @@ namespace Discord
                 return member;
             return null;
         }
-        public void UpdatePresence(PresenceModel model, DataStore dataStore, ConcurrentDictionary<ulong, CachedGuildUser> members = null)
-        {
-            members = members ?? _members;
-
-            CachedGuildUser member;
-            if (members.TryGetValue(model.User.Id, out member))
-                member.Update(model, UpdateSource.WebSocket);
-            else
-            {
-                var user = Discord.GetOrAddUser(model.User, dataStore);
-                member = new CachedGuildUser(this, user, model);
-                members[user.Id] = member;
-                user.AddRef();
-                DownloadedMemberCount++;
-            }
-        }
         public async Task DownloadMembersAsync()
         {
             if (!HasAllMembers)

src/Discord.Net/Extensions/EventExtensions.cs

@@ -1,56 +0,0 @@
-using System;
-using System.Threading.Tasks;
-
-namespace Discord.Extensions
-{
-    internal static class EventExtensions
-    {
-        //TODO: Optimize these for if there is only 1 subscriber (can we do this?)
-        //TODO: Could we maintain our own list instead of generating one on every invocation?
-        public static async Task RaiseAsync(this Func<Task> eventHandler)
-        {
-            var subscriptions = eventHandler?.GetInvocationList();
-            if (subscriptions != null)
-            {
-                for (int i = 0; i < subscriptions.Length; i++)
-                    await (subscriptions[i] as Func<Task>).Invoke().ConfigureAwait(false);
-            }
-        }
-        public static async Task RaiseAsync<T>(this Func<T, Task> eventHandler, T arg)
-        {
-            var subscriptions = eventHandler?.GetInvocationList();
-            if (subscriptions != null)
-            {
-                for (int i = 0; i < subscriptions.Length; i++)
-                    await (subscriptions[i] as Func<T, Task>).Invoke(arg).ConfigureAwait(false);
-            }
-        }
-        public static async Task RaiseAsync<T1, T2>(this Func<T1, T2, Task> eventHandler, T1 arg1, T2 arg2)
-        {
-            var subscriptions = eventHandler?.GetInvocationList();
-            if (subscriptions != null)
-            {
-                for (int i = 0; i < subscriptions.Length; i++)
-                    await (subscriptions[i] as Func<T1, T2, Task>).Invoke(arg1, arg2).ConfigureAwait(false);
-            }
-        }
-        public static async Task RaiseAsync<T1, T2, T3>(this Func<T1, T2, T3, Task> eventHandler, T1 arg1, T2 arg2, T3 arg3)
-        {
-            var subscriptions = eventHandler?.GetInvocationList();
-            if (subscriptions != null)
-            {
-                for (int i = 0; i < subscriptions.Length; i++)
-                    await (subscriptions[i] as Func<T1, T2, T3, Task>).Invoke(arg1, arg2, arg3).ConfigureAwait(false);
-            }
-        }
-        public static async Task RaiseAsync<T1, T2, T3, T4>(this Func<T1, T2, T3, T4, Task> eventHandler, T1 arg1, T2 arg2, T3 arg3, T4 arg4)
-        {
-            var subscriptions = eventHandler?.GetInvocationList();
-            if (subscriptions != null)
-            {
-                for (int i = 0; i < subscriptions.Length; i++)
-                    await (subscriptions[i] as Func<T1, T2, T3, T4, Task>).Invoke(arg1, arg2, arg3, arg4).ConfigureAwait(false);
-            }
-        }
-    }
-}

src/Discord.Net/Logging/LogManager.cs

@@ -1,5 +1,4 @@
-using Discord.Extensions;
-using System;
+using System;
 using System.Threading.Tasks;
 
 namespace Discord.Logging
@@ -8,7 +7,8 @@ namespace Discord.Logging
     {
         public LogSeverity Level { get; }
 
-        public event Func<LogMessage, Task> Message;
+        public event Func<LogMessage, Task> Message { add { _messageEvent.Add(value); } remove { _messageEvent.Remove(value); } }
+        private readonly AsyncEvent<Func<LogMessage, Task>> _messageEvent = new AsyncEvent<Func<LogMessage, Task>>();
 
         public LogManager(LogSeverity minSeverity)
         {
@@ -18,32 +18,32 @@ namespace Discord.Logging
         public async Task LogAsync(LogSeverity severity, string source, string message, Exception ex = null)
         {
             if (severity <= Level)
-                await Message.RaiseAsync(new LogMessage(severity, source, message, ex)).ConfigureAwait(false);
+                await _messageEvent.InvokeAsync(new LogMessage(severity, source, message, ex)).ConfigureAwait(false);
         }
         public async Task LogAsync(LogSeverity severity, string source, FormattableString message, Exception ex = null)
         {
             if (severity <= Level)
-                await Message.RaiseAsync(new LogMessage(severity, source, message.ToString(), ex)).ConfigureAwait(false);
+                await _messageEvent.InvokeAsync(new LogMessage(severity, source, message.ToString(), ex)).ConfigureAwait(false);
         }
         public async Task LogAsync(LogSeverity severity, string source, Exception ex)
         {
             if (severity <= Level)
-                await Message.RaiseAsync(new LogMessage(severity, source, null, ex)).ConfigureAwait(false);
+                await _messageEvent.InvokeAsync(new LogMessage(severity, source, null, ex)).ConfigureAwait(false);
         }
         async Task ILogger.LogAsync(LogSeverity severity, string message, Exception ex)
         {
             if (severity <= Level)
-                await Message.RaiseAsync(new LogMessage(severity, "Discord", message, ex)).ConfigureAwait(false);
+                await _messageEvent.InvokeAsync(new LogMessage(severity, "Discord", message, ex)).ConfigureAwait(false);
         }
         async Task ILogger.LogAsync(LogSeverity severity, FormattableString message, Exception ex)
         {
             if (severity <= Level)
-                await Message.RaiseAsync(new LogMessage(severity, "Discord", message.ToString(), ex)).ConfigureAwait(false);
+                await _messageEvent.InvokeAsync(new LogMessage(severity, "Discord", message.ToString(), ex)).ConfigureAwait(false);
         }
         async Task ILogger.LogAsync(LogSeverity severity, Exception ex)
         {
             if (severity <= Level)
-                await Message.RaiseAsync(new LogMessage(severity, "Discord", null, ex)).ConfigureAwait(false);
+                await _messageEvent.InvokeAsync(new LogMessage(severity, "Discord", null, ex)).ConfigureAwait(false);
         }
 
         public Task ErrorAsync(string source, string message, Exception ex = null)

src/Discord.Net/Utilities/AsyncEvent.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+    internal class AsyncEvent<T>
+    {
+        private readonly object _subLock = new object();
+        internal ImmutableArray<T> _subscriptions;
+
+        public IReadOnlyList<T> Subscriptions => _subscriptions;
+
+        public AsyncEvent()
+        {
+            _subscriptions = ImmutableArray.Create<T>();
+        }
+
+        public void Add(T subscriber)
+        {
+            lock (_subLock)
+                _subscriptions = _subscriptions.Add(subscriber);
+        }
+        public void Remove(T subscriber)
+        {
+            lock (_subLock)
+                _subscriptions = _subscriptions.Remove(subscriber);
+        }
+    }
+
+    internal static class EventExtensions
+    { 
+        public static async Task InvokeAsync(this AsyncEvent<Func<Task>> eventHandler)
+        {
+            var subscribers = eventHandler.Subscriptions;
+            if (subscribers.Count > 0)
+            {
+                for (int i = 0; i < subscribers.Count; i++)
+                    await subscribers[i].Invoke().ConfigureAwait(false);
+            }
+        }
+        public static async Task InvokeAsync<T>(this AsyncEvent<Func<T, Task>> eventHandler, T arg)
+        {
+            var subscribers = eventHandler.Subscriptions;
+            for (int i = 0; i < subscribers.Count; i++)
+                await subscribers[i].Invoke(arg).ConfigureAwait(false);
+        }
+        public static async Task InvokeAsync<T1, T2>(this AsyncEvent<Func<T1, T2, Task>> eventHandler, T1 arg1, T2 arg2)
+        {
+            var subscribers = eventHandler.Subscriptions;
+            for (int i = 0; i < subscribers.Count; i++)
+                await subscribers[i].Invoke(arg1, arg2).ConfigureAwait(false);
+        }
+        public static async Task InvokeAsync<T1, T2, T3>(this AsyncEvent<Func<T1, T2, T3, Task>> eventHandler, T1 arg1, T2 arg2, T3 arg3)
+        {
+            var subscribers = eventHandler.Subscriptions;
+            for (int i = 0; i < subscribers.Count; i++)
+                await subscribers[i].Invoke(arg1, arg2, arg3).ConfigureAwait(false);
+        }
+        public static async Task InvokeAsync<T1, T2, T3, T4>(this AsyncEvent<Func<T1, T2, T3, T4, Task>> eventHandler, T1 arg1, T2 arg2, T3 arg3, T4 arg4)
+        {
+            var subscribers = eventHandler.Subscriptions;
+            for (int i = 0; i < subscribers.Count; i++)
+                await subscribers[i].Invoke(arg1, arg2, arg3, arg4).ConfigureAwait(false);
+        }
+        public static async Task InvokeAsync<T1, T2, T3, T4, T5>(this AsyncEvent<Func<T1, T2, T3, T4, T5, Task>> eventHandler, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5)
+        {
+            var subscribers = eventHandler.Subscriptions;
+            for (int i = 0; i < subscribers.Count; i++)
+                await subscribers[i].Invoke(arg1, arg2, arg3, arg4, arg5).ConfigureAwait(false);
+        }
+    }
+}