Question

我已经制作了一个从MSMQueue读取消息的Windows服务，我需要并行执行此操作（两个线程应同时读取消息）。我怎样才能做到这一点？这是我的代码（几乎在书中）：

public partial class MyNewService : ServiceBase
    {
        System.Messaging.MessageQueue mq;
        System.Messaging.Message mes;

        public MyNewService()
        {
            InitializeComponent();

            if (MessageQueue.Exists("MyServer\\MyQueue"))
                mq = new System.Messaging.MessageQueue("MyServer\\MyQueue");

            mq.ReceiveCompleted += new ReceiveCompletedEventHandler(MyReceiveCompleted);
            mq.BeginReceive();

        }

        private static void MyReceiveCompleted(Object source, ReceiveCompletedEventArgs asyncResult)
        {
           try
           {
                MessageQueue mq = (MessageQueue)source;
                Message m = mq.EndReceive(asyncResult.AsyncResult);

                // TODO: Process the m message here

                // Restart the asynchronous receive operation.
                mq.BeginReceive();
            }
            catch(MessageQueueException)
            {
             // Handle sources of MessageQueueException.
            }

            return; 
         }

}

这是我的主要功能：

static class Program
  {
    static void Main()
    {
      ServiceBase[] ServicesToRun;
      ServicesToRun = new ServiceBase[] 
            { 
                new MyNewService() 
            };
      ServiceBase.Run(ServicesToRun);
    }
  }

Answer 1

是否有理由不能在多个线程上进行处理而不是在多个线程上出列？

这是 very 基本实现 - 它使用ThreadPool对项目进行排队，但您依靠ThreadPool的队列来处理线程数和工作项目的数量。根据许多其他因素，这可能不适合您的情况。

另外，请注意关于SetMaxThreads here的备注部分。

private static void MyReceiveCompleted(Object source, ReceiveCompletedEventArgs asyncResult)
{
   try
   {
       MessageQueue mq = (MessageQueue)source;
       Message m = mq.EndReceive(asyncResult.AsyncResult);

       // TODO: Process each message on a separate thread
       // This will immediately queue all items on the threadpool,
       // so there may be more threads spawned than you really want
       // Change how many items are allowed to process concurrently using ThreadPool.SetMaxThreads()
       System.Threading.ThreadPool.QueueUserWorkItem(new WaitCallback(doWork), m);


       // Restart the asynchronous receive operation.
       mq.BeginReceive();
   }
   catch(MessageQueueException)
   {
       // Handle sources of MessageQueueException.
   }

   return; 
}

private static void doWork(object message)
{
    // TODO: Actual implementation here.
}

Answer 2

我会在多个Windows服务上托管队列读取器的单线程实例。

通过这种方式，您可以通过启动其他服务来提高吞吐量，或者通过退回来减少吞吐量。这比尝试在代码中完成所有操作要简单得多。

多线程MSMQ读取

2 个答案: