Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / PageAsyncTask.cs / 1305376 / PageAsyncTask.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Web.UI { using System; using System.Collections; using System.Security; using System.Security.Permissions; using System.Threading; using System.Web; using System.Web.UI; using System.Web.Util; public sealed class PageAsyncTask { private BeginEventHandler _beginHandler; private EndEventHandler _endHandler; private EndEventHandler _timeoutHandler; private Object _state; private bool _executeInParallel; private PageAsyncTaskManager _taskManager; private int _completionMethodLock; private bool _started; private bool _completed; private bool _completedSynchronously; private AsyncCallback _completionCallback; private IAsyncResult _asyncResult; private Exception _error; public PageAsyncTask(BeginEventHandler beginHandler, EndEventHandler endHandler, EndEventHandler timeoutHandler, Object state) : this(beginHandler, endHandler, timeoutHandler, state, false) { } public PageAsyncTask(BeginEventHandler beginHandler, EndEventHandler endHandler, EndEventHandler timeoutHandler, Object state, bool executeInParallel) { if (beginHandler == null) { throw new ArgumentNullException("beginHandler"); } if (endHandler == null) { throw new ArgumentNullException("endHandler"); } _beginHandler = beginHandler; _endHandler = endHandler; _timeoutHandler = timeoutHandler; _state = state; _executeInParallel = executeInParallel; } public BeginEventHandler BeginHandler { get { return _beginHandler; } } public EndEventHandler EndHandler { get { return _endHandler; } } public EndEventHandler TimeoutHandler { get { return _timeoutHandler; } } public Object State { get { return _state; } } public bool ExecuteInParallel { get { return _executeInParallel; } } internal bool Started { get { return _started; } } internal bool CompletedSynchronously { get { return _completedSynchronously; } } internal bool Completed { get { return _completed; } } internal IAsyncResult AsyncResult { get { return _asyncResult; } } internal Exception Error { get { return _error; } } internal void Start(PageAsyncTaskManager manager, Object source, EventArgs args) { Debug.Assert(!_started); _taskManager = manager; _completionCallback = new AsyncCallback(this.OnAsyncTaskCompletion); _started = true; Debug.Trace("Async", "Start task"); try { IAsyncResult ar = _beginHandler(source, args, _completionCallback, _state); if (ar == null) { throw new InvalidOperationException(SR.GetString(SR.Async_null_asyncresult)); } if (_asyncResult == null) { // _asyncResult could be not null if already completed _asyncResult = ar; } } catch (Exception e) { Debug.Trace("Async", "Task failed to start"); _error = e; _completed = true; _completedSynchronously = true; _taskManager.TaskCompleted(true /*onCallerThread*/); // notify TaskManager // it is ok to say false (onCallerThread) above because this kind of // error completion will never be the last in ResumeTasks() } } private void OnAsyncTaskCompletion(IAsyncResult ar) { Debug.Trace("Async", "Task completed, CompletedSynchronously=" + ar.CompletedSynchronously); if (_asyncResult == null) { // _asyncResult could be null if the code not yet returned from begin method _asyncResult = ar; } CompleteTask(false /*timedOut*/); } internal void ForceTimeout(bool syncCaller) { Debug.Trace("Async", "Task timed out"); CompleteTask(true /*timedOut*/, syncCaller /*syncTimeoutCaller*/); } private void CompleteTask(bool timedOut) { CompleteTask(timedOut, false /*syncTimeoutCaller*/); } private void CompleteTask(bool timedOut, bool syncTimeoutCaller) { if (Interlocked.Exchange(ref _completionMethodLock, 1) != 0) { return; } bool needSetupThreadContext; bool responseEnded = false; if (timedOut) { needSetupThreadContext = !syncTimeoutCaller; } else { _completedSynchronously = _asyncResult.CompletedSynchronously; needSetupThreadContext = !_completedSynchronously; } // call the completion or timeout handler // when neeeded setup the thread context and lock // catch and remember all exceptions HttpApplication app = _taskManager.Application; try { if (needSetupThreadContext) { lock (app) { HttpApplication.ThreadContext threadContext = null; try { threadContext = app.OnThreadEnter(); if (timedOut) { if (_timeoutHandler != null) { _timeoutHandler(_asyncResult); } } else { _endHandler(_asyncResult); } } finally { if (threadContext != null) { threadContext.Leave(); } } } } else { if (timedOut) { if (_timeoutHandler != null) { _timeoutHandler(_asyncResult); } } else { _endHandler(_asyncResult); } } } catch (ThreadAbortException e) { _error = e; HttpApplication.CancelModuleException exceptionState = e.ExceptionState as HttpApplication.CancelModuleException; // Is this from Response.End() if (exceptionState != null && !exceptionState.Timeout) { // Mark the request as completed lock (app) { // Handle response end once. Skip if already initiated (previous AsyncTask) if (!app.IsRequestCompleted) { responseEnded = true; app.CompleteRequest(); } } // Clear the error for Response.End _error = null; } // ---- the exception. Async completion required (DDB 140655) Thread.ResetAbort(); } catch (Exception e) { _error = e; } // Complete the current async task _completed = true; _taskManager.TaskCompleted(_completedSynchronously /*onCallerThread*/); // notify TaskManager // Wait for pending AsyncTasks (DDB 140655) if (responseEnded) { _taskManager.CompleteAllTasksNow(false /*syncCaller*/); } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- Int16.cs
- cache.cs
- DataTableMappingCollection.cs
- ComplexPropertyEntry.cs
- ProgressChangedEventArgs.cs
- CompleteWizardStep.cs
- ExecutedRoutedEventArgs.cs
- Journaling.cs
- InputLangChangeRequestEvent.cs
- TraceInternal.cs
- StateItem.cs
- HostingEnvironmentException.cs
- ProgressPage.cs
- InstanceLockLostException.cs
- ProfileInfo.cs
- TimeStampChecker.cs
- LookupBindingPropertiesAttribute.cs
- XmlSchemaSimpleContent.cs
- ListViewCommandEventArgs.cs
- PinnedBufferMemoryStream.cs
- SmiEventSink_Default.cs
- MultipleViewProviderWrapper.cs
- LongTypeConverter.cs
- ParallelTimeline.cs
- MobileTextWriter.cs
- StringToken.cs
- RequestCachePolicy.cs
- CompletionCallbackWrapper.cs
- Operators.cs
- HMACSHA1.cs
- GacUtil.cs
- RestClientProxyHandler.cs
- WebBrowserContainer.cs
- DayRenderEvent.cs
- BypassElement.cs
- DispatcherExceptionEventArgs.cs
- TextEditorThreadLocalStore.cs
- OpenTypeLayoutCache.cs
- ColumnHeader.cs
- BitmapEffectCollection.cs
- BaseTemplateParser.cs
- recordstate.cs
- CounterCreationDataCollection.cs
- TrimSurroundingWhitespaceAttribute.cs
- NameTable.cs
- UpdateCommand.cs
- WSSecureConversation.cs
- UnknownBitmapDecoder.cs
- InfoCardTrace.cs
- TargetControlTypeCache.cs
- ColorPalette.cs
- Root.cs
- SqlDataSourceTableQuery.cs
- PriorityBinding.cs
- NativeMethods.cs
- ThrowOnMultipleAssignment.cs
- WebBrowserContainer.cs
- DesignerAutoFormatStyle.cs
- DbParameterHelper.cs
- AccessDataSourceView.cs
- InvokeMemberBinder.cs
- ADConnectionHelper.cs
- GeneratedView.cs
- UrlAuthFailedErrorFormatter.cs
- DataSetMappper.cs
- DurationConverter.cs
- ListViewContainer.cs
- DatatypeImplementation.cs
- Clipboard.cs
- CqlWriter.cs
- SqlBooleanizer.cs
- WebPartPersonalization.cs
- DataGridItemCollection.cs
- xmlfixedPageInfo.cs
- CatalogPart.cs
- TypeBinaryExpression.cs
- FontStretches.cs
- DelegateTypeInfo.cs
- XmlIlVisitor.cs
- NamedPipeConnectionPool.cs
- DynamicActivityXamlReader.cs
- RegexWorker.cs
- IImplicitResourceProvider.cs
- ManualResetEvent.cs
- _SafeNetHandles.cs
- AnnotationStore.cs
- ServiceHostingEnvironment.cs
- CriticalFinalizerObject.cs
- MgmtResManager.cs
- ItemMap.cs
- TextBox.cs
- WebServiceParameterData.cs
- DataGridCheckBoxColumn.cs
- SevenBitStream.cs
- StackOverflowException.cs
- DataGridColumnStyleMappingNameEditor.cs
- TrustManagerMoreInformation.cs
- AutomationElementIdentifiers.cs
- TextSelection.cs
- KeyManager.cs