我正在处理一个服务器端控制台应用程序,该应用程序从多个WCF服务接收数据,对其进行一些处理,然后使用SignalR通过单个连接将结果转发到IIS服务器.
I am working on a server side console application which receives data from multiple WCF services, does some work on it and then forwards the results to an IIS server over a single connection using SignalR.
我尝试使用生产者使用者模式来实现这一点,其中WCF服务是生产者,而使用SignalR发送数据的类是使用者.对于队列,我使用了 BlockingCollection .
I tried to implement this using the producer consumer pattern where the WCF services are the producers and the class sending the data using SignalR is the consumer. For the queue I used the BlockingCollection.
但是,当使用await/async在使用者的while循环中发送数据时,卡住了,直到所有其他线程都已将数据添加到队列中为止.
However, when using await/async to send the data in the consumer's while loop gets stuck until all other threads have finished adding data to the queue.
出于测试目的,我用Task.Delay(1000).Wait();或await Task.Delay(1000);替换了实际发送数据的代码,这两个代码也都卡住了. 一个简单的Thread.Sleep(1000);似乎可以正常工作,使我认为异步代码是问题所在.
For testing purposes I have replaced the code actually sending the data with a Task.Delay(1000).Wait(); or await Task.Delay(1000); which both get stuck as well. A simple Thread.Sleep(1000); seems to work just fine, leading me to think the asynchronous code is the problem.
所以我的问题是:是否有某些因素阻止在while循环中完成异步代码?我想念什么?
So my question is: Is there something preventing the asynchronous code being completed in the while loop? What am I missing?
我正在像这样启动使用者线程:
I'm starting the consumer thread like this:
new Thread(Worker).Start();以及消费者代码:
private void Worker() { while (!_queue.IsCompleted) { IMobileMessage msg = null; try { msg = _queue.Take(); } catch (InvalidOperationException) { } if (msg != null) { try { Trace.TraceInformation("Sending: {0}", msg.Name); Thread.Sleep(1000); // <-- works //Task.Delay(1000).Wait(); // <-- doesn't work msg.SentTime = DateTime.UtcNow; Trace.TraceInformation("X sent at {1}: {0}", msg.Name, msg.SentTime); } catch (Exception e) { TraceException(e); } } } }推荐答案
正如支出者正确指出的那样,BlockingCollection(顾名思义)仅用于阻塞代码,不适用于异步代码
As spender correctly pointed out, BlockingCollection (as the name implies) is intended only for use with blocking code, and does not work so well with asynchronous code.
有异步兼容的生产者/消费者队列,例如BufferBlock<T>.在这种情况下,我认为ActionBlock<T>会更好:
There are async-compatible producer/consumer queues, such as BufferBlock<T>. In this case, I would think ActionBlock<T> would be even better:
private ActionBlock<IMobileMsg> _block = new ActionBlock<IMobileMsg>(async msg => { try { Trace.TraceInformation("Sending: {0}", msg.Name); await Task.Delay(1000); msg.SentTime = DateTime.UtcNow; Trace.TraceInformation("X sent at {1}: {0}", msg.Name, msg.SentTime); } catch (Exception e) { TraceException(e); } });这将替换整个消耗线程和主循环.
This replaces your entire consuming thread and main loop.
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在使用BlockingCollection作为队列的使用者中等待异步方法
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