关于TASK与事件总线的同步
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悬赏园豆：100
[已关闭问题]
关闭于 2017-08-04 02:09
一、需求：
1、NamedPipe 接收消息后触发消息事件，将事件放到事件总线
2、事件总线通过订阅事件来处理事件
3、事件存在处理完后返回值的可能，也存在不返回
4、对于有返回的事件处理，响应 CancellationTokenSource 的 Cancel
5、对于无返回的事件处理，通过 等待响应超时 的方式触发 Cancel
二、问题：
响应的结果在响应处理时能获得，返回时失败
三、代码：
1、事件发布与同步等待代码
private string HandleRequestMessage(string message) { string result = null; CancellationTokenSource cancellationTokenSource = new CancellationTokenSource(MESSAGE_PROCESS_RESPONSE_TIMEOUT); PipeMessageEvent @event = new PipeMessageEvent(this._pipeManager.Pipename, this.PipeConnection.NativeHandle, message); Task task = new Task((() => Task.Run(AsyncResponseWaiter))); @event.Reponsed += (s, e) => { result = @event.Result; PublishStateEvent($"[Event]Response Info: {result}"); cancellationTokenSource.CancelAfter(SYNCHROUNOUSLY_TASK_DELAY_PERLOOP); }; this.PublishEvent(@event); task.RunSynchronously(); PublishStateEvent($"Response Info: [@event.Result]{@event.Result}, [result]{result}"); return $"[@event.Result]{@event.Result}, [result]{result}"; async Task AsyncResponseWaiter() { //Debug.WriteLine("begin AsyncResponseWaiter"); await Task.Factory.StartNew(() => { //Stopwatch watch = new Stopwatch(); //watch.Start(); while (!cancellationTokenSource.IsCancellationRequested) { Task.Delay(SYNCHROUNOUSLY_TASK_DELAY_PERLOOP); } //watch.Stop(); //Debug.WriteLine($"{cancellationTokenSource.IsCancellationRequested}, {watch.ElapsedMilliseconds}"); }, cancellationTokenSource.Token); //Debug.WriteLine("end AsyncResponseWaiter"); } }
2、事件发布处理代码
public void Publish(IEvent @event) { if(@event == null) { return; } Task.Factory.StartNew(() => OnEventTask(@event)); }
3、事件处理结果响应代码
public string Result { get; private set; } /// <summary> /// 消息处理 /// </summary> /// <param name="data"></param> public void Response(string data) { if(Interlocked.Decrement(ref this._responsedTimes) >= 0) { this.Result = data; this.Reponsed?.Invoke(this, EventArgs.Empty); } } /// <summary> /// 数据响应事件 /// </summary> public event EventHandler Reponsed;
