Fixed #5: Dynamic queues not reinitialized after reconnect

- Tasks in the TapetiWorker are no longer async, as that splits it in multiple tasks (and only because of a delay in GetChannel, there's no real point to the async code otherwise) which causes issues with publisher confirms

Tapeti/Connection/TapetiSubscriber.cs

@@ -26,6 +26,12 @@ namespace Tapeti.Connection
         }
 
 
+        public Task RebindQueues()
+        {
+            return BindQueues();
+        }
+
+
         public Task Resume()
         {
             if (consuming)

Tapeti/Connection/TapetiWorker.cs

@@ -62,18 +62,18 @@ namespace Tapeti.Connection
             if (string.IsNullOrEmpty(queueName))
                 throw new ArgumentNullException(nameof(queueName));
 
-            return taskQueue.Value.Add(async () =>
+            return taskQueue.Value.Add(() =>
             {
-                (await GetChannel()).BasicConsume(queueName, false, new TapetiConsumer(this, queueName, config.DependencyResolver, bindings, config.MessageMiddleware, config.CleanupMiddleware));
+                GetChannel().BasicConsume(queueName, false, new TapetiConsumer(this, queueName, config.DependencyResolver, bindings, config.MessageMiddleware, config.CleanupMiddleware));
-            }).Unwrap();
+            });
         }
 
 
         public Task Subscribe(IQueue queue)
         {
-            return taskQueue.Value.Add(async () =>
+            return taskQueue.Value.Add(() =>
             {
-                var channel = await GetChannel();
+                var channel = GetChannel();
 
                 if (queue.Dynamic)
                 {
@@ -101,30 +101,30 @@ namespace Tapeti.Connection
                         (binding as IBuildBinding)?.SetQueueName(queue.Name);
                     }
                 }
-            }).Unwrap();
+            });
         }
 
 
         public Task Respond(ulong deliveryTag, ConsumeResponse response)
         {
-            return taskQueue.Value.Add(async () =>
+            return taskQueue.Value.Add(() =>
             {
                 switch (response)
                 {
                     case ConsumeResponse.Ack:
-                        (await GetChannel()).BasicAck(deliveryTag, false);
+                        GetChannel().BasicAck(deliveryTag, false);
                         break;
 
                     case ConsumeResponse.Nack:
-                        (await GetChannel()).BasicNack(deliveryTag, false, false);
+                        GetChannel().BasicNack(deliveryTag, false, false);
                         break;
 
                     case ConsumeResponse.Requeue:
-                        (await GetChannel()).BasicNack(deliveryTag, false, true);
+                        GetChannel().BasicNack(deliveryTag, false, true);
                         break;
                 }
 
-            }).Unwrap();
+            });
         }
 
 
@@ -175,7 +175,7 @@ namespace Tapeti.Connection
             return MiddlewareHelper.GoAsync(
                 config.PublishMiddleware,
                 async (handler, next) => await handler.Handle(context, next),
-                () => taskQueue.Value.Add(async () =>
+                () => taskQueue.Value.Add(() =>
                 {
                     var body = messageSerializer.Serialize(context.Message, context.Properties);
                     Task<int> publishResultTask = null;
@@ -188,30 +188,25 @@ namespace Tapeti.Connection
                     else
                         mandatory = false;
 
-                    (await GetChannel(PublishMaxConnectAttempts)).BasicPublish(context.Exchange, context.RoutingKey, mandatory, context.Properties, body);
+                    GetChannel(PublishMaxConnectAttempts).BasicPublish(context.Exchange, context.RoutingKey, mandatory, context.Properties, body);
 
-                    if (publishResultTask != null)
+                    if (publishResultTask == null)
-                    {
+                        return;
-                        var timerCancellationSource = new CancellationTokenSource();
 
-                        if (await Task.WhenAny(publishResultTask, Task.Delay(MandatoryReturnTimeout, timerCancellationSource.Token)) == publishResultTask)
+                    if (!publishResultTask.Wait(MandatoryReturnTimeout))
-                        {
+                        throw new TimeoutException($"Timeout while waiting for basic.return for message with class {context.Message?.GetType().FullName ?? "null"} and Id {context.Properties.MessageId}");
-                            timerCancellationSource.Cancel();
 
-                            var replyCode = publishResultTask.Result;
 
-                            // There is no RabbitMQ.Client.Framing.Constants value for this "No route" reply code
+                    var replyCode = publishResultTask.Result;
-                            // at the time of writing...
-                            if (replyCode == 312)
-                                throw new NoRouteException($"Mandatory message with class {context.Message?.GetType().FullName ?? "null"} does not have a route");
 
-                            if (replyCode > 0)
+                    // There is no RabbitMQ.Client.Framing.Constants value for this "No route" reply code
-                                throw new NoRouteException($"Mandatory message with class {context.Message?.GetType().FullName ?? "null"} could not be delivery, reply code {replyCode}");
+                    // at the time of writing...
-                        }
+                    if (replyCode == 312)
-                        else
+                        throw new NoRouteException($"Mandatory message with class {context.Message?.GetType().FullName ?? "null"} does not have a route");
-                            throw new TimeoutException($"Timeout while waiting for basic.return for message with class {context.Message?.GetType().FullName ?? "null"} and Id {context.Properties.MessageId}");
+
-                    }
+                    if (replyCode > 0)
-                }).Unwrap());
+                        throw new NoRouteException($"Mandatory message with class {context.Message?.GetType().FullName ?? "null"} could not be delivery, reply code {replyCode}");
+                }));
             // ReSharper restore ImplicitlyCapturedClosure
         }
 
@@ -219,7 +214,7 @@ namespace Tapeti.Connection
         /// Only call this from a task in the taskQueue to ensure IModel is only used 
         /// by a single thread, as is recommended in the RabbitMQ .NET Client documentation.
         /// </remarks>
-        private async Task<IModel> GetChannel(int? maxAttempts = null)
+        private IModel GetChannel(int? maxAttempts = null)
         {
             if (channelInstance != null)
                 return channelInstance;
@@ -233,6 +228,7 @@ namespace Tapeti.Connection
                 UserName = ConnectionParams.Username,
                 Password = ConnectionParams.Password,
                 AutomaticRecoveryEnabled = true, // The created connection is an IRecoverable
+                TopologyRecoveryEnabled = false, // We'll manually redeclare all queues in the Reconnect event to update the internal state for dynamic queues
                 RequestedHeartbeat = 30
             };
 
@@ -277,7 +273,7 @@ namespace Tapeti.Connection
                     if (maxAttempts.HasValue && attempts > maxAttempts.Value)
                         throw;
 
-                    await Task.Delay(ReconnectDelay);
+                    Thread.Sleep(ReconnectDelay);
                 }
             }
 

Tapeti/TapetiConnection.cs

@@ -14,7 +14,7 @@ namespace Tapeti
         public TapetiConnectionParams Params { get; set; }
 
         private readonly Lazy<TapetiWorker> worker;
-
+        private TapetiSubscriber subscriber;
 
         public TapetiConnection(IConfig config)
         {
@@ -36,8 +36,11 @@ namespace Tapeti
 
         public async Task<ISubscriber> Subscribe(bool startConsuming = true)
         {
-            var subscriber = new TapetiSubscriber(() => worker.Value, config.Queues.ToList());
+            if (subscriber == null)
-            await subscriber.BindQueues();
+            {
+                subscriber = new TapetiSubscriber(() => worker.Value, config.Queues.ToList());
+                await subscriber.BindQueues();
+            }
 
             if (startConsuming)
                 await subscriber.Resume();
@@ -46,9 +49,9 @@ namespace Tapeti
         }
 
 
-        public ISubscriber SubscribeSync()
+        public ISubscriber SubscribeSync(bool startConsuming = true)
         {
-            return Subscribe().Result;
+            return Subscribe(startConsuming).Result;
         }
 
 
@@ -97,17 +100,23 @@ namespace Tapeti
 
         protected virtual void OnConnected(EventArgs e)
         {
-            Connected?.Invoke(this, e);
+            Task.Run(() => Connected?.Invoke(this, e));
         }
 
         protected virtual void OnReconnected(EventArgs e)
         {
-            Reconnected?.Invoke(this, e);
+            Task.Run(() =>
+            {
+                subscriber?.RebindQueues().ContinueWith((t) =>
+                {
+                    Reconnected?.Invoke(this, e);
+                });
+            });
         }
 
         protected virtual void OnDisconnected(EventArgs e)
         {
-            Disconnected?.Invoke(this, e);
+            Task.Run(() => Disconnected?.Invoke(this, e));
         }
     }
 }