Improve async and reconnect stability. Added support for websocket 1012

src/Discord.Net.Commands/CommandService.cs

@@ -51,14 +51,14 @@ namespace Discord.Commands
                     .Description("Returns information about commands.")
                     .Do(async e =>
                     {
-						Channel replyChannel = _config.HelpMode == HelpMode.Public ? e.Channel : await e.User.CreateChannel();
+						Channel replyChannel = _config.HelpMode == HelpMode.Public ? e.Channel : await e.User.CreateChannel().ConfigureAwait(false);
 						if (e.Args.Length > 0) //Show command help
 						{
 							var map = _map.GetItem(string.Join(" ", e.Args));
 							if (map != null)
-								await ShowCommandHelp(map, e.User, e.Channel, replyChannel);
+								await ShowCommandHelp(map, e.User, e.Channel, replyChannel).ConfigureAwait(false);
 							else
-								await replyChannel.SendMessage("Unable to display help: Unknown command.");
+								await replyChannel.SendMessage("Unable to display help: Unknown command.").ConfigureAwait(false);
 						}
                         else //Show general help							
 							await ShowGeneralHelp(e.User, e.Channel, replyChannel);

src/Discord.Net.Net45/Discord.Net.csproj

@@ -509,6 +509,9 @@
     <Compile Include="..\Discord.Net\Net\TimeoutException.cs">
       <Link>Net\TimeoutException.cs</Link>
     </Compile>
+    <Compile Include="..\Discord.Net\Net\WebSocketException.cs">
+      <Link>Net\WebSockets\WebSocketException.cs</Link>
+    </Compile>
     <Compile Include="..\Discord.Net\Net\WebSockets\GatewaySocket.cs">
       <Link>Net\WebSockets\GatewaySocket.cs</Link>
     </Compile>

src/Discord.Net/API/Client/GatewaySocket/OpCodes.cs

@@ -19,6 +19,6 @@
         /// <summary> C←S - Used to notify a client that they must reconnect to another gateway. </summary>
         Redirect = 7,
         /// <summary> C→S - Used to request all members that were withheld by large_threshold </summary>
-        RequestGuildMembers = 8
+        RequestGuildMembers = 99
     }
 }

src/Discord.Net/DiscordClient.Obsolete.cs

@@ -159,7 +159,7 @@ namespace Discord.Legacy
             if (messages == null) throw new ArgumentNullException(nameof(messages));
 
             foreach (var message in messages)
-                await message.Delete();
+                await message.Delete().ConfigureAwait(false);
         }
         
         [Obsolete("Use Channel.DownloadMessages")]

src/Discord.Net/DiscordClient.cs

@@ -128,7 +128,7 @@ namespace Discord
 			Connected += async (s, e) =>
 			{
                 ClientAPI.CancelToken = CancelToken;
-				await SendStatus();
+				await SendStatus().ConfigureAwait(false);
 			};
 
             //Extensibility
@@ -250,7 +250,7 @@ namespace Discord
                 }
 
                 //Cache other stuff
-                var regionsResponse = (await ClientAPI.Send(new GetVoiceRegionsRequest()));
+                var regionsResponse = (await ClientAPI.Send(new GetVoiceRegionsRequest()).ConfigureAwait(false));
                 _regions = regionsResponse.Select(x => new Region(x.Id, x.Name, x.Hostname, x.Port))
                     .ToDictionary(x => x.Id);
                 break;

src/Discord.Net/Models/Channel.cs

@@ -213,7 +213,7 @@ namespace Discord
         #region Invites
         /// <summary> Gets all active (non-expired) invites to this server. </summary>
         public async Task<IEnumerable<Invite>> GetInvites()
-            => (await Server.GetInvites()).Where(x => x.Channel.Id == Id);
+            => (await Server.GetInvites().ConfigureAwait(false)).Where(x => x.Channel.Id == Id);
 
         /// <summary> Creates a new invite to this channel. </summary>
         /// <param name="maxAge"> Time (in seconds) until the invite expires. Set to null to never expire. </param>

src/Discord.Net/Net/WebSocketException.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Discord.Net
+{
+    public class WebSocketException : Exception
+    {
+        public int Code { get; }
+        public string Reason { get; }
+
+        public WebSocketException(int code, string reason)
+            : base(GenerateMessage(code, reason))
+        {
+            Code = code;
+            Reason = reason;
+        }
+        
+        private static string GenerateMessage(int? code, string reason)
+        {
+            if (!String.IsNullOrEmpty(reason))
+                return $"Received close code {code}: {reason}";
+            else
+                return $"Received close code {code}";
+        }
+    }
+}

src/Discord.Net/Net/WebSockets/GatewaySocket.cs

@@ -13,8 +13,10 @@ namespace Discord.Net.WebSockets
 	{
         private int _lastSequence;
 		private string _sessionId;
+        private string _token;
+        private int _reconnects;
 
-        public string Token { get; internal set; }
+        public string Token { get { return _token; } internal set { _token = value; _sessionId = null; } }
 
 		public GatewaySocket(DiscordClient client, JsonSerializer serializer, Logger logger)
 			: base(client, serializer, logger)
@@ -29,20 +31,21 @@ namespace Discord.Net.WebSockets
         public async Task Connect()
         {
             await BeginConnect().ConfigureAwait(false);
-			SendIdentify(Token);
+            if (_sessionId == null)
+                SendIdentify(Token);
+            else
+                SendResume();
         }
-		private async Task Redirect()
-        {
-            await BeginConnect().ConfigureAwait(false);
-			SendResume();
-		}
 		private async Task Reconnect()
 		{
 			try
 			{
 				var cancelToken = ParentCancelToken.Value;
-				await Task.Delay(_client.Config.ReconnectDelay, cancelToken).ConfigureAwait(false);
-				while (!cancelToken.IsCancellationRequested)
+                if (_reconnects++ == 0)
+				    await Task.Delay(_client.Config.ReconnectDelay, cancelToken).ConfigureAwait(false);
+                else
+                    await Task.Delay(_client.Config.FailedReconnectDelay, cancelToken).ConfigureAwait(false);
+                while (!cancelToken.IsCancellationRequested)
 				{
 					try
                     {
@@ -69,8 +72,15 @@ namespace Discord.Net.WebSockets
             tasks.Add(HeartbeatAsync(CancelToken));
             await _taskManager.Start(tasks, _cancelTokenSource).ConfigureAwait(false);
         }
+        protected override Task Cleanup()
+        {
+            var ex = _taskManager.Exception;
+            if (ex != null && (ex as WebSocketException)?.Code != 1012)
+                _sessionId = null; //Reset session unless close code 1012
+            return base.Cleanup();
+        }
 
-		protected override async Task ProcessMessage(string json)
+        protected override async Task ProcessMessage(string json)
 		{
 			await base.ProcessMessage(json).ConfigureAwait(false);
 			var msg = JsonConvert.DeserializeObject<WebSocketMessage>(json);
@@ -85,9 +95,10 @@ namespace Discord.Net.WebSockets
 						JToken token = msg.Payload as JToken;
 						if (msg.Type == "READY")
 						{
-							var payload = token.ToObject<ReadyEvent>(_serializer);
+                            _reconnects = 0;
+                            var payload = token.ToObject<ReadyEvent>(_serializer);
 							_sessionId = payload.SessionId;
-							_heartbeatInterval = payload.HeartbeatInterval;
+                            _heartbeatInterval = payload.HeartbeatInterval;
 						}
 						else if (msg.Type == "RESUMED")
 						{
@@ -106,7 +117,7 @@ namespace Discord.Net.WebSockets
 						{
 							Host = payload.Url;
 							Logger.Info("Redirected to " + payload.Url);
-							await Redirect().ConfigureAwait(false);
+							await Reconnect().ConfigureAwait(false);
 						}
 					}
 					break;

src/Discord.Net/Net/WebSockets/WS4NetEngine.cs

@@ -83,13 +83,7 @@ namespace Discord.Net.WebSockets
         {
             Exception ex;
             if (e is ClosedEventArgs)
-            {
-                int code = (e as ClosedEventArgs).Code;
-                string reason = (e as ClosedEventArgs).Reason;
-                if (String.IsNullOrEmpty(reason))
-                    reason = "No reason";
-                ex = new Exception($"Received close code {code}: {reason}");
-            }
+                ex = new WebSocketException((e as ClosedEventArgs).Code, (e as ClosedEventArgs).Reason);
             else
                 ex = new Exception($"Connection lost");
             _taskManager.SignalError(ex, isUnexpected: true);

src/Discord.Net/Net/WebSockets/WebSocket.cs

@@ -125,7 +125,7 @@ namespace Discord.Net.WebSockets
 			_cancelTokenSource = null;
 			_connectedEvent.Reset();
 
-            if (oldState == ConnectionState.Connected)
+            if (oldState == ConnectionState.Connecting || oldState == ConnectionState.Connected)
             {
                 var ex = _taskManager.Exception;
                 if (ex == null)