NetMQ订户与发布的消息

Question

我有其产生在结构的PUB插座消息发布服务器类，用下面的代码阻断：

this.context = NetMQContext.Create(); 
this.pubSocket = this.context.CreatePublisherSocket(); 
var portNumber = this.installerSettings.PublisherPort; 
this.pubSocket.Bind("tcp://127.0.0.1:" + portNumber); 

发送使用messagePublishingServer.Publish(message)消息执行：

this.pubSocket.SendMoreFrame(string.Empty).SendFrame(message); 

以下xBehave测试...

[Scenario] 
    public void PublishMessageScenario() 
    { 
     MessagePublishingServer messagePublishingServer = null; 
     NetMQContext context; 
     NetMQ.Sockets.SubscriberSocket subSocket = null; 
     string receivedMessage = null; 

     "Given a running message publishing server"._(() => 
     { 
      var installerSettingsManager = A.Fake<IInstallerSettingsManager>(); 
      var settings = new InstallerSettings { PublisherPort = "5348" }; 
      A.CallTo(() => installerSettingsManager.Settings).Returns(settings); 
      messagePublishingServer = new MessagePublishingServer(installerSettingsManager); 
     }); 

     "And a subscriber connected to the publishing server"._(() => 
     { 
      context = NetMQContext.Create(); 
      subSocket = context.CreateSubscriberSocket(); 
      subSocket.Options.ReceiveHighWatermark = 1000; 
      subSocket.Connect("tcp://127.0.0.1:5348"); 
      subSocket.Subscribe(string.Empty); 
     }); 

     "When publishing a message"._(() => 
     { 
      messagePublishingServer.Publish("test message"); 

      // Receive the topic 
      subSocket.ReceiveFrameString(); 

      // and the message 
      receivedMessage = subSocket.ReceiveFrameString(); 
     }); 

     "Then the subscriber must have received it"._(() => 
     { 
      receivedMessage.Should().NotBeNullOrEmpty(); 
      receivedMessage.Should().Be("test message"); 
     }); 
    } 

... bl在我发现意想不到的第一个subSocket.ReceiveFrameString()。订阅者套接字是否应该在发布接收消息之前排队发布的消息？

Answer 1

出版商就像收音机，如果没有连接，当出版商出版你错过的消息订阅。我的建议是在用户连接后进行100ms睡眠（仅用于测试）。

Answer 2

从源（ReceivingSocketExtensions.cs ）：

/// Receive a single frame from socket, blocking until one arrives, and decode as a string using ... 
    public static string ReceiveFrameString([NotNull] this IReceivingSocket socket) 

和

/// If no message is immediately available, return <c>false</c>. 
    public static bool TryReceiveFrameString([NotNull] this IReceivingSocket socket, out string frameString)