mvc5 源码解析 mvchandler的执行2-2

Posted 2022-01-02 nnyang

我们从application获取的时候查看stepmanager的实现类

IHttpHandler applicationInstance = HttpApplicationFactory.GetApplicationInstance(httpContext);

/ System.Web.HttpApplicationFactory
internal static IHttpHandler GetApplicationInstance(HttpContext context)

    if (HttpApplicationFactory._customApplication != null)
    
        return HttpApplicationFactory._customApplication;
    
    if (context.Request.IsDebuggingRequest)
    
        return new HttpDebugHandler();
    
    HttpApplicationFactory._theApplicationFactory.EnsureInited();
    HttpApplicationFactory._theApplicationFactory.EnsureAppStartCalled(context);
    return HttpApplicationFactory._theApplicationFactory.GetNormalApplicationInstance(context);

/ System.Web.HttpApplicationFactory
private HttpApplication GetNormalApplicationInstance(HttpContext context)

    HttpApplication httpApplication = null;
    if (!this._freeList.TryTake(out httpApplication))
    
　　　　//创建application
        httpApplication = (HttpApplication)HttpRuntime.CreateNonPublicInstance(this._theApplicationType);
        using (new ApplicationImpersonationContext())
        
　　　　　　　　//初始化application
            httpApplication.InitInternal(context, this._state, this._eventHandlerMethods);
        
    
    if (AppSettings.UseTaskFriendlySynchronizationContext)
    
        httpApplication.ApplicationInstanceConsumersCounter = new CountdownTask(1);
        Task arg_8A_0 = httpApplication.ApplicationInstanceConsumersCounter.Task;
        Action<Task, object> arg_8A_1;
        if ((arg_8A_1 = HttpApplicationFactory.<>c.<>9__34_0) == null)
        
            arg_8A_1 = (HttpApplicationFactory.<>c.<>9__34_0 = new Action<Task, object>(HttpApplicationFactory.<>c.<>9.<GetNormalApplicationInstance>b__34_0));
        
        arg_8A_0.ContinueWith(arg_8A_1, httpApplication, TaskContinuationOptions.ExecuteSynchronously);
    
    return httpApplication;

  

初始化application

// System.Web.HttpApplication
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)
                
                    try
                    
                        context.HideRequestResponse = true;
                        this._hideRequestResponse = true;
                        this.InitIntegratedModules();
                        goto IL_6B;
                    
                    finally
                    
                        context.HideRequestResponse = false;
                        this._hideRequestResponse = false;
                    
                
                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);
　　　　　　　　//判断是集成模式还是经典模式分别初始化不同的stepmanager
            if (HttpRuntime.UseIntegratedPipeline)
            
                this._stepManager = new HttpApplication.PipelineStepManager(this);
            
            else
            
                this._stepManager = new HttpApplication.ApplicationStepManager(this);
            
　　　　　　　　//创建步骤
            this._stepManager.BuildSteps(this._resumeStepsWaitCallback);
        
        finally
        
            this._initInternalCompleted = true;
            context.ConfigurationPath = null;
            this._initContext.ApplicationInstance = null;
            this._initContext = null;
        
    
    catch
    
        throw;
    

创建步骤及执行步骤

经典模式PipelineStepManager管道创建步骤

internal override void BuildSteps(WaitCallback stepCallback)
    
　　　　//加入步骤各个事件
        ArrayList arrayList = new ArrayList();
        HttpApplication application = this._application;
        UrlMappingsSection urlMappings = RuntimeConfig.GetConfig().UrlMappings;
        bool flag = urlMappings.IsEnabled && urlMappings.UrlMappings.Count > 0;
        arrayList.Add(new HttpApplication.ValidateRequestExecutionStep(application));
        arrayList.Add(new HttpApplication.ValidatePathExecutionStep(application));
        if (flag)
        
            arrayList.Add(new HttpApplication.UrlMappingsExecutionStep(application));
        
        application.CreateEventExecutionSteps(HttpApplication.EventBeginRequest, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventAuthenticateRequest, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventDefaultAuthentication, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPostAuthenticateRequest, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventAuthorizeRequest, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPostAuthorizeRequest, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventResolveRequestCache, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPostResolveRequestCache, arrayList);
　　　
        arrayList.Add(new HttpApplication.MapHandlerExecutionStep(application));
        application.CreateEventExecutionSteps(HttpApplication.EventPostMapRequestHandler, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventAcquireRequestState, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPostAcquireRequestState, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPreRequestHandlerExecute, arrayList);
        arrayList.Add(application.CreateImplicitAsyncPreloadExecutionStep());
　　　　//加入mvchandler执行的步骤事件
        arrayList.Add(new HttpApplication.CallHandlerExecutionStep(application));
        application.CreateEventExecutionSteps(HttpApplication.EventPostRequestHandlerExecute, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventReleaseRequestState, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPostReleaseRequestState, arrayList);
        arrayList.Add(new HttpApplication.CallFilterExecutionStep(application));
        application.CreateEventExecutionSteps(HttpApplication.EventUpdateRequestCache, arrayList);
        application.CreateEventExecutionSteps(HttpApplication.EventPostUpdateRequestCache, arrayList);
        this._endRequestStepIndex = arrayList.Count;
        application.CreateEventExecutionSteps(HttpApplication.EventEndRequest, arrayList);
        arrayList.Add(new HttpApplication.NoopExecutionStep());
        this._execSteps = new HttpApplication.IExecutionStep[arrayList.Count];
        arrayList.CopyTo(this._execSteps);
        this._resumeStepsWaitCallback = stepCallback;
    

CallHandlerExecutionStep

void HttpApplication.IExecutionStep.Execute()

    

        HttpContext context = this._application.Context;

        IHttpHandler handler = context.Handler;

        if (EtwTrace.IsTraceEnabled(4, 4))

        

            EtwTrace.Trace(EtwTraceType.ETW_TYPE_HTTPHANDLER_ENTER, context.WorkerRequest);

        

        if (handler != null && HttpRuntime.UseIntegratedPipeline)

        

            IIS7WorkerRequest iIS7WorkerRequest = context.WorkerRequest as IIS7WorkerRequest;

            if (iIS7WorkerRequest != null && iIS7WorkerRequest.IsHandlerExecutionDenied())

            

                this._sync = true;

                HttpException ex = new HttpException(403, SR.GetString("Handler_access_denied"));

                ex.SetFormatter(new PageForbiddenErrorFormatter(context.Request.Path, SR.GetString("Handler_access_denied")));

                throw ex;

            

        

        if (handler == null)

        

            this._sync = true;

            return;

        

        if (handler is IHttpAsyncHandler)

        

            IHttpAsyncHandler httpAsyncHandler = (IHttpAsyncHandler)handler;

            this._sync = false;

            this._handler = httpAsyncHandler;

            Func<HttpContext, AsyncCallback, object, IAsyncResult> func = AppVerifier.WrapBeginMethod<HttpContext>(this._application, new Func<HttpContext, AsyncCallback, object, IAsyncResult>(httpAsyncHandler.BeginProcessRequest));

            this._asyncStepCompletionInfo.Reset();

            context.SyncContext.AllowVoidAsyncOperations();

            IAsyncResult asyncResult;

            try

            
　　　　　　　　　　//执行beginprocessrequest方法
                asyncResult = func(context, this._completionCallback, null);

            

            catch

            

                context.SyncContext.ProhibitVoidAsyncOperations();

                throw;

            

            bool flag;

            bool flag2;

            this._asyncStepCompletionInfo.RegisterBeginUnwound(asyncResult, out flag, out flag2);

            if (flag)

            

                this._sync = true;

                this._handler = null;

                context.SyncContext.ProhibitVoidAsyncOperations();

                try

                

                    if (flag2)

                    

                        httpAsyncHandler.EndProcessRequest(asyncResult);

                    

                    this._asyncStepCompletionInfo.ReportError();

                

                finally

                

                    HttpApplication.CallHandlerExecutionStep.SuppressPostEndRequestIfNecessary(context);

                    context.Response.GenerateResponseHeadersForHandler();

                

                if (EtwTrace.IsTraceEnabled(4, 4))

                

                    EtwTrace.Trace(EtwTraceType.ETW_TYPE_HTTPHANDLER_LEAVE, context.WorkerRequest);

                    return;

                

            

        

        else

        

            this._sync = true;

            context.SyncContext.SetSyncCaller();

            try

            

                handler.ProcessRequest(context);

            

            finally

            

                context.SyncContext.ResetSyncCaller();

                if (EtwTrace.IsTraceEnabled(4, 4))

                

                    EtwTrace.Trace(EtwTraceType.ETW_TYPE_HTTPHANDLER_LEAVE, context.WorkerRequest);

                

                HttpApplication.CallHandlerExecutionStep.SuppressPostEndRequestIfNecessary(context);

                context.Response.GenerateResponseHeadersForHandler();

            

        

    

执行步骤

internal override void ResumeSteps(Exception error)
    
        bool flag = false;
        bool flag2 = true;
        HttpApplication application = this._application;
        CountdownTask applicationInstanceConsumersCounter = application.ApplicationInstanceConsumersCounter;
        HttpContext context = application.Context;
        ThreadContext threadContext = null;
        AspNetSynchronizationContextBase syncContext = context.SyncContext;
        try
        
            if (applicationInstanceConsumersCounter != null)
            
                applicationInstanceConsumersCounter.MarkOperationPending();
            
            using (syncContext.AcquireThreadLock())
            
                try
                
                    threadContext = application.OnThreadEnter();
                
                catch (Exception ex)
                
                    if (error == null)
                    
                        error = ex;
                    
                
                try
                
                    try
                    
                        while (true)
                        
                            if (syncContext.Error != null)
                            
                                error = syncContext.Error;
                                syncContext.ClearError();
                            
                            if (error != null)
                            
                                application.RecordError(error);
                                error = null;
                            
                            if (syncContext.PendingCompletion(this._resumeStepsWaitCallback))
                            
                                goto IL_123;
                            
                            if (this._currentStepIndex < this._endRequestStepIndex && (context.Error != null || this._requestCompleted))
                            
                                context.Response.FilterOutput();
                                this._currentStepIndex = this._endRequestStepIndex;
                            
                            else
                            
                                this._currentStepIndex++;
                            
                            if (this._currentStepIndex >= this._execSteps.Length)
                            
                                break;
                            
                            this._numStepCalls++;
                            syncContext.Enable();
　　　　　　　　　　　　　　　　　　//执行每个事件中的Excute方法
                            error = application.ExecuteStep(this._execSteps[this._currentStepIndex], ref flag2);
                            if (!flag2)
                            
                                goto IL_123;
                            
                            this._numSyncStepCalls++;
                        
                        flag = true;
                        IL_123:;
                    
                    finally
                    
                        if (flag)
                        
                            context.RaiseOnRequestCompleted();
                        
                        if (threadContext != null)
                        
                            try
                            
                                threadContext.DisassociateFromCurrentThread();
                            
                            catch
                            
                            
                        
                    
                
                catch
                
                    throw;
                
            
            if (flag)
            
                context.RaiseOnPipelineCompleted();
                context.Unroot();
                application.AsyncResult.Complete(this._numStepCalls == this._numSyncStepCalls, null, null);
                application.ReleaseAppInstance();
            
        
        finally
        
            if (applicationInstanceConsumersCounter != null)
            
                applicationInstanceConsumersCounter.MarkOperationCompleted();
            
        
    

 

   集成模式同理