I. Introduction

One of the advantages of using work queues is that they can process queues in parallel. If a lot of tasks are piled up, we just need to add more workers. The extension is very simple. This example uses multithreading to create multichannels and bind queues to achieve the goal of multiple workers.

II. Examples

2.1 environmental preparation

Install RabbitMQ.Client on NuGet.

2.2 factory

Add a factory class RabbitMQFactory:

    /// <summary>
    /// Multiplexing technology(Multiplexing)Purpose: to avoid creating multiple TCP It will result in the waste and overload of system resources, so as to make effective use of them TCP Connect.
    /// </summary>
    public static class RabbitMQFactory
    {
        private static IConnection sharedConnection;
        private static int ChannelCount { get; set; }
        private static readonly object _locker = new object();

        public static IConnection SharedConnection
        {
            get
            {
                if (ChannelCount >= 1000)
                {
                    if (sharedConnection != null && sharedConnection.IsOpen)
                    {
                        sharedConnection.Close();
                    }
                    sharedConnection = null;
                    ChannelCount = 0;
                }
                if (sharedConnection == null)
                {
                    lock (_locker)
                    {
                        if (sharedConnection == null)
                        {
                            sharedConnection = GetConnection();
                            ChannelCount++;
                        }
                    }
                }
                return sharedConnection;
            }
        }

        private static IConnection GetConnection()
        {
            var factory = new ConnectionFactory
            {
                HostName = "192.168.2.242",
                UserName = "hello",
                Password = "world",
                Port = AmqpTcpEndpoint.UseDefaultPort,//5672
                VirtualHost = ConnectionFactory.DefaultVHost,//Use default:"/"
                Protocol = Protocols.DefaultProtocol,
                AutomaticRecoveryEnabled = true
            };
            return factory.CreateConnection();
        }
    }

2.3 main window

The code is as follows:

    public partial class RabbitMQMultithreading : Form
    {
        public delegate void ListViewDelegate<T>(T obj);

        public RabbitMQMultithreading()
        {
            InitializeComponent();
        }

        /// <summary>
        /// ShowMessage heavy load
        /// </summary>
        /// <param name="msg"></param>
        private void ShowMessage(string msg)
        {
            if (InvokeRequired)
            {
                BeginInvoke(new ListViewDelegate<string>(ShowMessage), msg);
            }
            else
            {
                ListViewItem item = new ListViewItem(new string[] { DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss ffffff"), msg });
                lvwMsg.Items.Insert(0, item);
            }
        }

        /// <summary>
        /// ShowMessage heavy load
        /// </summary>
        /// <param name="format"></param>
        /// <param name="args"></param>
        private void ShowMessage(string format, params object[] args)
        {
            if (InvokeRequired)
            {
                BeginInvoke(new MethodInvoker(delegate ()
                {
                    ListViewItem item = new ListViewItem(new string[] { DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss ffffff"), string.Format(format, args) });
                    lvwMsg.Items.Insert(0, item);
                }));
            }
            else
            {
                ListViewItem item = new ListViewItem(new string[] { DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss ffffff"), string.Format(format, args) });
                lvwMsg.Items.Insert(0, item);
            }
        }

        /// <summary>
        /// Producer
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnSend_Click(object sender, EventArgs e)
        {
            int messageCount = 100;
            var factory = new ConnectionFactory
            {
                HostName = "192.168.2.242",
                UserName = "hello",
                Password = "world",
                Port = AmqpTcpEndpoint.UseDefaultPort,//5672
                VirtualHost = ConnectionFactory.DefaultVHost,//Use default:"/"
                Protocol = Protocols.DefaultProtocol,
                AutomaticRecoveryEnabled = true
            };
            using (var connection = factory.CreateConnection())
            {
                using (var channel = connection.CreateModel())
                {
                    channel.QueueDeclare(queue: "hello", durable: true, exclusive: false, autoDelete: false, arguments: null);
                    string message = "Hello World";
                    var body = Encoding.UTF8.GetBytes(message);
                    for (int i = 1; i <= messageCount; i++)
                    {
                        channel.BasicPublish(exchange: "", routingKey: "hello", basicProperties: null, body: body);
                        ShowMessage($"Send {message}");
                    }
                }
            }
        }

        /// <summary>
        /// Consumer
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void btnReceive_Click(object sender, EventArgs e)
        {
            Random random = new Random();
            int rallyNumber = random.Next(1, 1000);
            int channelCount = 0;

            await Task.Run(() =>
            {
                try
                {
                    int asyncCount = 10;
                    List<Task<bool>> tasks = new List<Task<bool>>();
                    var connection = RabbitMQFactory.SharedConnection;
                    for (int i = 1; i <= asyncCount; i++)
                    {
                        tasks.Add(Task.Factory.StartNew(() => MessageWorkItemCallback(connection, rallyNumber)));
                    }
                    Task.WaitAll(tasks.ToArray());

                    string syncResultMsg = $"Assembly number {rallyNumber} The horn has blown--" +
                        $"Number of successful channels opened this time:{tasks.Count(s => s.Result == true)}，" +
                        $"Number of channel failures opened this time:{tasks.Count() - tasks.Count(s => s.Result == true)}" +
                        $"Cumulative channel open success:{channelCount + tasks.Count(s => s.Result == true)}";
                    ShowMessage(syncResultMsg);
                }
                catch (Exception ex)
                {
                    ShowMessage($"Assembly number {rallyNumber} Abnormal consumption:{ex.Message}");
                }
            });
        }

        /// <summary>
        /// Asynchronous method
        /// </summary>
        /// <param name="state"></param>
        /// <param name="rallyNumber"></param>
        /// <returns></returns>
        private bool MessageWorkItemCallback(object state, int rallyNumber)
        {
            bool syncResult = false;
            IModel channel = null;
            try
            {
                IConnection connection = state as IConnection;
                //Out of commission using (channel = connection.CreateModel())To create a channel RabbitMQ Automatic recovery channel. 
                channel = connection.CreateModel();
                channel.QueueDeclare(queue: "hello", durable: true, exclusive: false, autoDelete: false, arguments: null);
                channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
                var consumer = new EventingBasicConsumer(channel);
                consumer.Received += (model, ea) =>
                {
                    var message = Encoding.UTF8.GetString(ea.Body);
                    Thread.Sleep(1000);
                    ShowMessage($"Assembly number {rallyNumber} Received {message}");
                    channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
                };
                channel.BasicConsume(queue: "hello", autoAck: false, consumer: consumer);
                syncResult = true;
            }
            catch (Exception ex)
            {
                syncResult = false;
                ShowMessage(ex.Message);
            }
            return syncResult;
        }
    }

2.4 operation results

More than a few times, the consumer can increase the channel and improve the consumption ability.