什么是HttpTransportElement的RequestInitializationTimeout？ MSDN说：
获取或设置时间跨度，指定在超时之前请求初始化必须完成的时间。
究竟是什么＆＃34;请求初始化＆＃34;？为什么我要设置此属性？
答案 0 :(得分：7)
没有关于RequestInitializationTimeout的明确文档。
SharedHttpTransportManager.IsCompatible的源代码中有关于RequestInitializationTimeout检查的注释：
// We are NOT checking the RequestInitializationTimeout here since the HttpChannelListener should be handle them // individually. However, some of the scenarios might be impacted, e.g., if we have one endpoint with high RequestInitializationTimeout // and the other is just normal, the first endpoint might be occupying all the receiving loops, then the requests to the normal endpoint // will experience timeout issues. The mitigation for this issue is that customers should be able to increase the MaxPendingAccepts number.
如果我们检查将TimeoutException分配给OnParseComplete内部与requestException一起传递的HttpRequestContext.SetMessage(message, requestException)，我们可以看到：
new TimeoutException(SR.GetString(
SR.RequestInitializationTimeoutReached,
this.HttpRequestContext.Listener.RequestInitializationTimeout,
"RequestInitializationTimeout",
typeof(HttpTransportBindingElement).Name))
和有关SR.RequestInitializationTimeoutReached System.Private.ServiceModel的异常消息是：
The initialization process of the request message timed out after {0}. To increase this quota, use the '{1}' property on the '{2}'.
将被格式化为以下格式：
The initialization process of the request message timed out after 00:00:10. To increase this quota, use the 'RequestInitializationTimeout' property on the 'HttpTransportBindingElement'.
如果遵循源代码，我们可以在EmptyHttpPipeline中找到它的用法。
EmptyHttpPipeline.EmptyHttpPipeline 如果存在RequestInitializationTimeout TimeSpan（而不是禁用它的default 00:00:00 ），则将IOThreadTimer设置为{{ 1}}设置为dueTime滴答声，将OnRequestInitializationTimeout TimeSpan回调和Action（实际的this对象）设置为EmptyHttpPipeline。
callbackState在尝试通过取消EmptyHttpPipeline.OnParseComplete来调用requestInitializationTimer方法时进行检查。如果有一个计时器，并且之前已被取消或过期，它将创建一个if (this.httpRequestContext.Listener.RequestInitializationTimeout != HttpTransportDefaults.RequestInitializationTimeout)
{
this.requestInitializationTimer = new IOThreadTimer(onRequestInitializationTimeout, this, false);
this.requestInitializationTimer.Set(this.httpRequestContext.Listener.RequestInitializationTimeout);
}
并分配给TimeoutException，并将其与requestException一起传递给HttpPipeline.HttpRequestContext.SetMessage：
message正在OnParseComplete方法内使用EnqueueMessageAsyncResult.CompleteParseAndEnqueue protected override void OnParseComplete(Message message, Exception requestException)
{
if (!this.CancelRequestInitializationTimer() && requestException == null)
{
requestException = FxTrace.Exception.AsError(new TimeoutException(SR.GetString(
SR.RequestInitializationTimeoutReached,
this.HttpRequestContext.Listener.RequestInitializationTimeout,
"RequestInitializationTimeout",
typeof(HttpTransportBindingElement).Name)));
}
this.HttpRequestContext.SetMessage(message, requestException);
}
在HandleParseIncomingMessage内部调用EnqueueMessageAsyncResult.End方法。调用EnqueueMessageAsyncResult时会创建EmptyHttpPipeline.BeginProcessInboundRequest对象，该对象在EmptyHttpPipeline.EndProcessInboundRequest内部终止。
BeginProcessInboundRequest和EndProcessInboundRequest AsyncCallbackEnqueueMessageAsyncResult.CompleteParseAndEnqueue internal override IAsyncResult BeginProcessInboundRequest(
ReplyChannelAcceptor replyChannelAcceptor,
Action dequeuedCallback,
AsyncCallback callback,
object state)
{
this.TraceBeginProcessInboundRequestStart();
return new EnqueueMessageAsyncResult(replyChannelAcceptor, dequeuedCallback, this, callback, state);
}
internal override void EndProcessInboundRequest(IAsyncResult result)
{
// It will trigger HandleParseIncomingMessage AsyncCallback,
// that will call CompleteParseAndEnqueue
EnqueueMessageAsyncResult.End(result);
this.TraceProcessInboundRequestStop();
}
正在使用CancelRequestInitializationTimer方法进行检查，如果没有设置计时器，则返回true；如果先前已取消，则返回false，否则调用void CompleteParseAndEnqueue(IAsyncResult result)
{
using (DiagnosticUtility.ShouldUseActivity ? ServiceModelActivity.BoundOperation(this.CallbackActivity) : null)
{
Exception requestException;
Message message = this.pipeline.EndParseIncomingMesssage(result, out requestException);
if ((message == null) && (requestException == null))
{
throw FxTrace.Exception.AsError(
new ProtocolException(
SR.GetString(SR.MessageXmlProtocolError),
new XmlException(SR.GetString(SR.MessageIsEmpty))));
}
// Here the EmptyHttpPipeline.OnParseComplete is being invoked
this.pipeline.OnParseComplete(message, requestException);
this.acceptor.Enqueue(this.pipeline.HttpRequestContext, this.dequeuedCallback, true);
}
}
方法进行检查，如果已取消，则返回true；如果计时器过期，则返回false。
EmptyHttpPipeline.CancelRequestInitializationTimer IOThreadTimer.Cancel在OnRequestInitializationTimeout方法内，我们可以看到它取消了protected bool CancelRequestInitializationTimer()
{
if (this.requestInitializationTimer == null)
{
return true;
}
if (this.requestInitializationTimerCancelled)
{
return false;
}
bool result = this.requestInitializationTimer.Cancel();
this.requestInitializationTimerCancelled = true;
return result;
}
，从而中止了HttpPipeline.httpRequestContext：
EmptyHttpPipeline.OnRequestInitializationTimeout HttpPipelineHttpPipeline.Cancel static void OnRequestInitializationTimeout(object obj)
{
Fx.Assert(obj != null, "obj should not be null.");
HttpPipeline thisPtr = (HttpPipeline)obj;
thisPtr.Cancel();
}
EmptyHttpPipeline对象？如果我们使用接受EmptyHttpPipeline且没有HttpPipeline.CreateHttpPipeline的静态TransportIntegrationHandler来设置public virtual void Cancel()
{
this.httpRequestContext.Abort();
}
，则会得到HttpRequestContext.HttpMessagesSupported：
transportIntegrationHandler = null在CreateHttpPipeline上调用HttpRequestContext.InitializeHttpPipeline：
HttpRequestContext.InitializeHttpPipeline public static HttpPipeline CreateHttpPipeline(HttpRequestContext httpRequestContext, TransportIntegrationHandler transportIntegrationHandler, bool isWebSocketTransport)
{
if (transportIntegrationHandler == null)
{
Fx.Assert(!isWebSocketTransport, "isWebSocketTransport should be false if there's no HTTP message handler existing.");
if (httpRequestContext.HttpMessagesSupported)
{
return new HttpMessageSupportedHttpPipeline(httpRequestContext);
}
return new EmptyHttpPipeline(httpRequestContext);
}
return NormalHttpPipeline.CreatePipeline(httpRequestContext, transportIntegrationHandler, isWebSocketTransport);
}
使用HttpRequestContext requestContext
HttpContextReceivedAsyncResult内部的HttpContextReceivedAsyncResult<TListenerChannel>.ProcessHttpContextAsync（传入HttpChannelListener<TListenerChannel>.transportIntegrationHandler构造函数）中调用
HttpContextReceivedAsyncResult<TListenerChannel>.ProcessHttpContextAsync public void InitializeHttpPipeline(TransportIntegrationHandler transportIntegrationHandler)
{
this.httpPipeline = HttpPipeline.CreateHttpPipeline(this, transportIntegrationHandler, this.IsWebSocketRequest);
}
所有这些使我们得出以下结论：当创建AsyncCompletionResult ProcessHttpContextAsync()
{
bool abort = false;
try
{
this.context.InitializeHttpPipeline(this.listener.transportIntegrationHandler);
...
}
...
}
时没有HttpPipeline且没有TransportIntegrationHandler的{{1}}时，则新的HttpMessagesSupported HttpRequestContext / EmptyHttpPipeline的对象将有一个超时（如果设置了RequestInitializationTimeout ，则为），并在{内使用BeginProcessInboundRequest设置消息时设置了异常{1}}。