//梳理下asp.net 对请求的处理流程： [Guid("08a2c56f-7c16-41c1-a8be-432917a1a2d1"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] [ComImport] public interface IISAPIRuntime { [SecurityPermission(SecurityAction.LinkDemand, Unrestricted = true), SecurityPermission(SecurityAction.InheritanceDemand, Unrestricted = true)] void StartProcessing(); [SecurityPermission(SecurityAction.LinkDemand, Unrestricted = true), SecurityPermission(SecurityAction.InheritanceDemand, Unrestricted = true)] void StopProcessing(); [SecurityPermission(SecurityAction.LinkDemand, Unrestricted = true), SecurityPermission(SecurityAction.InheritanceDemand, Unrestricted = true)] [return: MarshalAs(UnmanagedType.I4)] int ProcessRequest([In] IntPtr ecb, [MarshalAs(UnmanagedType.I4)] [In] int useProcessModel); [SecurityPermission(SecurityAction.LinkDemand, Unrestricted = true), SecurityPermission(SecurityAction.InheritanceDemand, Unrestricted = true)] void DoGCCollect(); } [Guid("15eb8d20-d4ed-4855-a276-91a75a696955"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] [ComImport] internal interface IISAPIRuntime2 { void StartProcessing(); void StopProcessing(); [return: MarshalAs(UnmanagedType.I4)] int ProcessRequest([In] IntPtr ecb, [MarshalAs(UnmanagedType.I4)] [In] int useProcessModel); void DoGCCollect(); } public sealed class ISAPIRuntime : MarshalByRefObject, IISAPIRuntime, IISAPIRuntime2, IRegisteredObject{ //ISAPIRuntime.ProcessRequest 这是iis调用.net的入口 这实现了一个com接口 [SecurityPermission(SecurityAction.LinkDemand, Unrestricted = true)] public int ProcessRequest(IntPtr ecb, int iWRType) { IntPtr intPtr = IntPtr.Zero; if (iWRType == 2) { intPtr = ecb; ecb = UnsafeNativeMethods.GetEcb(intPtr); } ISAPIWorkerRequest iSAPIWorkerRequest = null; int result; try { bool useOOP = iWRType == 1; //根据IIS穿过来的非托管参数 创建WorkRequest对象 iSAPIWorkerRequest = ISAPIWorkerRequest.CreateWorkerRequest(ecb, useOOP); iSAPIWorkerRequest.Initialize(); string appPathTranslated = iSAPIWorkerRequest.GetAppPathTranslated(); string appDomainAppPathInternal = HttpRuntime.AppDomainAppPathInternal; if (appDomainAppPathInternal == null || StringUtil.EqualsIgnoreCase(appPathTranslated, appDomainAppPathInternal)) { //调用HttpRuntime.ProcessRequest 来处理请求 HttpRuntime.ProcessRequestNoDemand(iSAPIWorkerRequest); result = 0; } else { HttpRuntime.ShutdownAppDomain(ApplicationShutdownReason.PhysicalApplicationPathChanged, SR.GetString("Hosting_Phys_Path_Changed", new object[] { appDomainAppPathInternal, appPathTranslated })); result = 1; } } catch (Exception ex) { try { WebBaseEvent.RaiseRuntimeError(ex, this); } catch { } if (iSAPIWorkerRequest == null || !(iSAPIWorkerRequest.Ecb == IntPtr.Zero)) { throw; } if (intPtr != IntPtr.Zero) { UnsafeNativeMethods.SetDoneWithSessionCalled(intPtr); } if (ex is ThreadAbortException) { Thread.ResetAbort(); } result = 0; } return result; } } /*HttpWorkerRequest有: abstract class ISAPIWorkerRequest， class ISAPIWorkerRequestInProc：ISAPIWorkerRequest， class ISAPIWorkerRequestInProcForIIS6：ISAPIWorkerRequestInProc， class ISAPIWorkerRequestInProcForIIS7：ISAPIWorkerRequestInProcForIIS6， class ISAPIWorkerRequestOutOfProc：ISAPIWorkerRequest 几种实现 ， 封装了大部分.net 托管代码和iis本地代码数据交互的操作 （包括客户端数据的读写，连接状态的判断，客户端IP的获取等操作） */ /*HttpRuntime.ProcessRequestNoDemand 这个里面判断了 是否有请求队列 如果就将当前请求放入队列 从队列中取出合适的请求 */ internal static void ProcessRequestNoDemand(HttpWorkerRequest wr) { RequestQueue requestQueue = HttpRuntime._theRuntime._requestQueue; wr.UpdateInitialCounters(); if (requestQueue != null) { wr = requestQueue.GetRequestToExecute(wr); } if (wr != null) { HttpRuntime.CalculateWaitTimeAndUpdatePerfCounter(wr); //记录最新的请求开始时间到HttpWorkerRequest._startTime wr.ResetStartTime(); //开始处理请求对象 ProcessRequestNow 只是简单的封装了 //HttpRuntime.ProcessRequestInternal(wr) 实例方法 HttpRuntime.ProcessRequestNow(wr); } } //RequestQueue.GetRequestToExecute internal HttpWorkerRequest GetRequestToExecute(HttpWorkerRequest wr) { int num; int num2; //从当前线程池里取出可用线程数量 ThreadPool.GetAvailableThreads(out num, out num2); int num3; if (this._iis6) { num3 = num; //iis6及以下 忽略异步线程数 } else { num3 = ((num2 > num) ? num : num2);// } //队列中无待处理请求 直接返回 if (num3 >= this._minExternFreeThreads && this._count == 0) { return wr; } bool flag = RequestQueue.IsLocal(wr); if (flag && num3 >= this._minLocalFreeThreads && this._count == 0) { return wr; } //队列中待处理请求数量超限 拒绝当前请求 if (this._count >= this._queueLimit) { HttpRuntime.RejectRequestNow(wr, false); return null; } //当前请求入队 this.QueueRequest(wr, flag); //从队列中取出一个待处理请求 if (num3 >= this._minExternFreeThreads) { wr = this.DequeueRequest(false); } else if (num3 >= this._minLocalFreeThreads) { wr = this.DequeueRequest(true); } else { //尝试增加更多的处理线程 wr = null; this.ScheduleMoreWorkIfNeeded(); } return wr; } //HttpRuntime.ProcessRequestInternal private void ProcessRequestInternal(HttpWorkerRequest wr) { Interlocked.Increment(ref this._activeRequestCount); //当前HttpRuntime 对象已经销毁 返回错误 if (this._disposingHttpRuntime) { try { wr.SendStatus(503, "Server Too Busy"); wr.SendKnownResponseHeader(12, "text/html; charset=utf-8"); byte[] bytes = Encoding.ASCII.GetBytes("<html><body>Server Too Busy</body></html>"); byte[] expr_45 = bytes; wr.SendResponseFromMemory(expr_45, expr_45.Length); wr.FlushResponse(true); wr.EndOfRequest(); } finally { Interlocked.Decrement(ref this._activeRequestCount); } return; } HttpContext httpContext; try { //生成 HttpContext 对象 httpContext = new HttpContext(wr, false); } catch { try { wr.SendStatus(400, "Bad Request"); wr.SendKnownResponseHeader(12, "text/html; charset=utf-8"); byte[] bytes2 = Encoding.ASCII.GetBytes("<html><body>Bad Request</body></html>"); byte[] expr_A5 = bytes2; wr.SendResponseFromMemory(expr_A5, expr_A5.Length); wr.FlushResponse(true); wr.EndOfRequest(); return; } finally { Interlocked.Decrement(ref this._activeRequestCount); } } wr.SetEndOfSendNotification(this._asyncEndOfSendCallback, httpContext); HostingEnvironment.IncrementBusyCount(); try { try { //如果是第一次请求 根据系统配置做一些初始化工作 //最终调用HttpRuntime.FirstRequestInit this.EnsureFirstRequestInit(httpContext); } catch { if (!httpContext.Request.IsDebuggingRequest) { throw; } } //简单的封装响应写入流 httpContext.Response.InitResponseWriter(); //关键点-获取请求处理Handler 其中包括application初始化 httpModule执行 IHttpHandler applicationInstance = HttpApplicationFactory.GetApplicationInstance(httpContext); if (applicationInstance == null) { throw new HttpException(SR.GetString("Unable_create_app_object")); } if (EtwTrace.IsTraceEnabled(5, 1)) { EtwTrace.Trace(EtwTraceType.ETW_TYPE_START_HANDLER, httpContext.WorkerRequest, applicationInstance.GetType().FullName, "Start"); } //判断是否异步Handler if (applicationInstance is IHttpAsyncHandler) { //调用异步处理流程 HttpApplication.BeginProcessRequest IHttpAsyncHandler httpAsyncHandler = (IHttpAsyncHandler)applicationInstance; httpContext.AsyncAppHandler = httpAsyncHandler; httpAsyncHandler.BeginProcessRequest(httpContext, this._handlerCompletionCallback, httpContext); } else { //直接处理 HttpApplication.ProcessRequest applicationInstance.ProcessRequest(httpContext); //请求处理结束，做些收尾工作 this.FinishRequest(httpContext.WorkerRequest, httpContext, null); } } catch (Exception e) { httpContext.Response.InitResponseWriter(); this.FinishRequest(wr, httpContext, e); } } //HttpRuntime.FirstRequestInit 设置一些应用程序的基本配置 private void FirstRequestInit(HttpContext context) { Exception ex = null; if (HttpRuntime.InitializationException == null && this._appDomainId != null) { try { using (new ApplicationImpersonationContext()) { CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture; CultureInfo currentUICulture = Thread.CurrentThread.CurrentUICulture; try { //初始化HTTP配置 HttpRuntime.InitHttpConfiguration(); HttpRuntime.CheckApplicationEnabled(); this.CheckAccessToTempDirectory(); this.InitializeHealthMonitoring(); //初始化请求队列 this.InitRequestQueue(); this.InitTrace(context); HealthMonitoringManager.StartHealthMonitoringHeartbeat(); HttpRuntime.RestrictIISFolders(context); this.PreloadAssembliesFromBin(); this.InitHeaderEncoding(); HttpEncoder.InitializeOnFirstRequest(); RequestValidator.InitializeOnFirstRequest(); if (context.WorkerRequest is ISAPIWorkerRequestOutOfProc) { ProcessModelSection arg_8E_0 = RuntimeConfig.GetMachineConfig().ProcessModel; } } finally { Thread.CurrentThread.CurrentUICulture = currentUICulture; HttpRuntime.SetCurrentThreadCultureWithAssert(currentCulture); } } } catch (ConfigurationException ex) { } catch (Exception ex2) { ex = new HttpException(SR.GetString("XSP_init_error", new object[] { ex2.Message }), ex2); } finally { } } if (HttpRuntime.InitializationException != null) { throw new HttpException(HttpRuntime.InitializationException.Message, HttpRuntime.InitializationException); } if (ex != null) { HttpRuntime.InitializationException = ex; throw ex; } HttpRuntime.AddAppDomainTraceMessage("FirstRequestInit"); } //HttpApplicationFactory.GetApplicationInstance internal static IHttpHandler GetApplicationInstance(HttpContext context) { if (HttpApplicationFactory._customApplication != null) { return HttpApplicationFactory._customApplication; } if (context.Request.IsDebuggingRequest) { return new HttpDebugHandler(); } //这里面关联了global.asax 并解析了Application_OnStart // Application_Start Application_OnEnd Application_End Session_OnEnd Session_End 等一些(object,EventArgs)方法 HttpApplicationFactory._theApplicationFactory.EnsureInited(); //调用Application_Start方法 HttpApplicationFactory._theApplicationFactory.EnsureAppStartCalled(context); //获取HttpApplication return HttpApplicationFactory._theApplicationFactory.GetNormalApplicationInstance(context); } //HttpApplicationFactory.GetNormalApplicationInstance private HttpApplication GetNormalApplicationInstance(HttpContext context) { //从池中获取可用 HttpApplication 如果没有再创建，用完后会入池的 HttpApplication httpApplication = null; Stack freeList = this._freeList; lock (freeList) { if (this._numFreeAppInstances > 0) { httpApplication = (HttpApplication)this._freeList.Pop(); this._numFreeAppInstances--; if (this._numFreeAppInstances < this._minFreeAppInstances) { this._minFreeAppInstances = this._numFreeAppInstances; } } } if (httpApplication == null) { httpApplication = (HttpApplication)HttpRuntime.CreateNonPublicInstance(this._theApplicationType); using (new ApplicationImpersonationContext()) { //初始化 HttpApplication 主要完成的工作时HttpModule的初始化和处理请求过程中每个步骤触发事件处理程序的准备 //在 HttpModule.Init可以注册HttpApplication 各个阶段的事件 httpApplication.InitInternal(context, this._state, this._eventHandlerMethods); } } if (AppSettings.UseTaskFriendlySynchronizationContext) { httpApplication.ApplicationInstanceConsumersCounter = new CountdownTask(1); Task arg_DD_0 = httpApplication.ApplicationInstanceConsumersCounter.Task; Action<Task, object> arg_DD_1; if ((arg_DD_1 = HttpApplicationFactory.<>c.<>9__37_0) == null) { arg_DD_1 = (HttpApplicationFactory.<>c.<>9__37_0 = new Action<Task, object>(HttpApplicationFactory.<>c.<>9.<GetNormalApplicationInstance>b__37_0)); } arg_DD_0.ContinueWith(arg_DD_1, httpApplication, TaskContinuationOptions.ExecuteSynchronously); } return httpApplication; } // HttpApplication.InitInternal internal void InitInternal(HttpContext context, HttpApplicationState state, MethodInfo[] handlers) { this._state = state; PerfCounters.IncrementCounter(AppPerfCounter.PIPELINES); try { try { this._initContext = context; this._initContext.ApplicationInstance = this; context.ConfigurationPath = context.Request.ApplicationPathObject; using (new DisposableHttpContextWrapper(context)) { if (HttpRuntime.UseIntegratedPipeline) //判断iis管道模式 { try { context.HideRequestResponse = true; this._hideRequestResponse = true; //初始化HttpModule HttpApplication.InitModulesCommon this.InitIntegratedModules(); goto IL_6B; } finally { context.HideRequestResponse = false; this._hideRequestResponse = false; } } //初始化HttpModule 最终调用了 HttpApplication.InitModulesCommon this.InitModules(); IL_6B: if (handlers != null) { this.HookupEventHandlersForApplicationAndModules(handlers); } this._context = context; if (HttpRuntime.UseIntegratedPipeline && this._context != null) { this._context.HideRequestResponse = true; } this._hideRequestResponse = true; try { this.Init(); } catch (Exception error) { this.RecordError(error); } } if (HttpRuntime.UseIntegratedPipeline && this._context != null) { this._context.HideRequestResponse = false; } this._hideRequestResponse = false; this._context = null; this._resumeStepsWaitCallback = new WaitCallback(this.ResumeStepsWaitCallback); if (HttpRuntime.UseIntegratedPipeline) { this._stepManager = new HttpApplication.PipelineStepManager(this); } else { this._stepManager = new HttpApplication.ApplicationStepManager(this); } this._stepManager.BuildSteps(this._resumeStepsWaitCallback); } finally { this._initInternalCompleted = true; context.ConfigurationPath = null; this._initContext.ApplicationInstance = null; this._initContext = null; } } catch { throw; } } //HttpApplication.InitModulesCommon private void InitModulesCommon() { int count = this._moduleCollection.Count; for (int i = 0; i < count; i++) { this._currentModuleCollectionKey = this._moduleCollection.GetKey(i); this._moduleCollection[i].Init(this); //调用各注册Module的IHttpModule.Init方法初始化 } this._currentModuleCollectionKey = null; this.InitAppLevelCulture(); }