Code:
/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / AspNetSynchronizationContext.cs / 2 / AspNetSynchronizationContext.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- using System; using System.ComponentModel; using System.Security.Permissions; using System.Threading; using System.Web; using System.Web.Util; namespace System.Web { internal class AspNetSynchronizationContext : SynchronizationContext { private HttpApplication _application; private bool _disabled; private bool _syncCaller; private bool _invalidOperationEncountered; private int _pendingCount; private Exception _error; private WaitCallback _lastCompletionWorkItemCallback; internal AspNetSynchronizationContext(HttpApplication app) { _application = app; } private void CallCallback(SendOrPostCallback callback, Object state) { // don't take app lock for sync caller to avoid deadlocks in case they poll for result if (_syncCaller) { CallCallbackPossiblyUnderLock(callback, state); } else { lock (_application) { CallCallbackPossiblyUnderLock(callback, state); } } } private void CallCallbackPossiblyUnderLock(SendOrPostCallback callback, Object state) { HttpApplication.ThreadContext threadContext = null; try { threadContext = _application.OnThreadEnter(); try { callback(state); } catch (Exception e) { _error = e; } } finally { if (threadContext != null) { threadContext.Leave(); } } } internal int PendingOperationsCount { get { return _pendingCount; } } internal Exception Error { get { return _error; } } internal void ClearError() { _error = null; } internal void SetLastCompletionWorkItem(WaitCallback callback) { Debug.Assert(_lastCompletionWorkItemCallback == null); // only one at a time _lastCompletionWorkItemCallback = callback; } public override void Send(SendOrPostCallback callback, Object state) { #if DBG Debug.Trace("Async", "Send"); Debug.Trace("AsyncStack", "Send from:\r\n" + System.Environment.StackTrace); #endif CallCallback(callback, state); } public override void Post(SendOrPostCallback callback, Object state) { #if DBG Debug.Trace("Async", "Post"); Debug.Trace("AsyncStack", "Post from:\r\n" + System.Environment.StackTrace); #endif CallCallback(callback, state); } #if DBG [EnvironmentPermission(SecurityAction.Assert, Unrestricted=true)] private void CreateCopyDumpStack() { Debug.Trace("Async", "CreateCopy"); Debug.Trace("AsyncStack", "CreateCopy from:\r\n" + System.Environment.StackTrace); } #endif public override SynchronizationContext CreateCopy() { #if DBG CreateCopyDumpStack(); #endif AspNetSynchronizationContext context = new AspNetSynchronizationContext(_application); context._disabled = _disabled; context._syncCaller = _syncCaller; return context; } public override void OperationStarted() { if (_invalidOperationEncountered || (_disabled && _pendingCount == 0)) { _invalidOperationEncountered = true; throw new InvalidOperationException(SR.GetString(SR.Async_operation_disabled)); } Interlocked.Increment(ref _pendingCount); #if DBG Debug.Trace("Async", "OperationStarted(count=" + _pendingCount + ")"); Debug.Trace("AsyncStack", "OperationStarted(count=" + _pendingCount + ") from:\r\n" + System.Environment.StackTrace); #endif } public override void OperationCompleted() { if (_invalidOperationEncountered || (_disabled && _pendingCount == 0)) { // throw from operation started could cause extra operation completed return; } bool lastOperationCompleted = (Interlocked.Decrement(ref _pendingCount) == 0); #if DBG Debug.Trace("Async", "OperationCompleted(count=" + _pendingCount + ")"); Debug.Trace("AsyncStack", "OperationCompleted(count=" + _pendingCount + ") from:\r\n" + System.Environment.StackTrace); #endif if (lastOperationCompleted && _lastCompletionWorkItemCallback != null) { // notify (once) about the last completion to resume the async work WaitCallback cb = _lastCompletionWorkItemCallback; _lastCompletionWorkItemCallback = null; Debug.Trace("Async", "Queueing LastCompletionWorkItemCallback"); ThreadPool.QueueUserWorkItem(cb); } } internal bool Enabled { get { return !_disabled; } } internal void Enable() { _disabled = false; } internal void Disable() { _disabled = true; } internal void SetSyncCaller() { _syncCaller = true; } internal void ResetSyncCaller() { _syncCaller = false; } } }
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- TextRangeSerialization.cs
- AspNetSynchronizationContext.cs
- Vector3dCollection.cs
- PriorityBinding.cs
- BooleanExpr.cs
- HtmlLink.cs
- Substitution.cs
- ListBox.cs
- XmlSchemaSimpleTypeUnion.cs
- FtpRequestCacheValidator.cs
- HexParser.cs
- SQLSingleStorage.cs
- EntityContainerRelationshipSetEnd.cs
- TrackingConditionCollection.cs
- HttpWebRequestElement.cs
- ExpressionPrinter.cs
- FullTextState.cs
- DateBoldEvent.cs
- DrawingAttributes.cs
- OneWayBindingElementImporter.cs
- ListViewDataItem.cs
- ScalarType.cs
- StaticSiteMapProvider.cs
- RenderData.cs
- LinkArea.cs
- CapabilitiesUse.cs
- XPathSelfQuery.cs
- ExceptionUtility.cs
- OraclePermissionAttribute.cs
- FixedSOMLineCollection.cs
- DynamicRouteExpression.cs
- BinaryNode.cs
- HttpDebugHandler.cs
- PropertyInfoSet.cs
- DiscoveryMessageProperty.cs
- UserControl.cs
- OpCodes.cs
- CompilerScopeManager.cs
- _BaseOverlappedAsyncResult.cs
- DBDataPermission.cs
- unsafenativemethodsother.cs
- CustomCategoryAttribute.cs
- RegexMatch.cs
- EnumBuilder.cs
- DbTransaction.cs
- DataGridViewSortCompareEventArgs.cs
- ListenerAdapter.cs
- DLinqTableProvider.cs
- Nullable.cs
- XsdDataContractImporter.cs
- ArrayExtension.cs
- XamlSerializerUtil.cs
- VoiceObjectToken.cs
- CodeNamespaceImportCollection.cs
- WebPartChrome.cs
- MenuEventArgs.cs
- ExpressionBuilder.cs
- QilUnary.cs
- IntegerValidator.cs
- TextBlock.cs
- XmlSchemaCollection.cs
- BigInt.cs
- Transform3DGroup.cs
- PropertyPathWorker.cs
- PropertyTab.cs
- SplitterPanel.cs
- NameValueFileSectionHandler.cs
- CookielessHelper.cs
- DeliveryRequirementsAttribute.cs
- MenuItem.cs
- CryptoApi.cs
- IPAddress.cs
- MethodBody.cs
- SafeFileMappingHandle.cs
- StorageComplexPropertyMapping.cs
- BinHexDecoder.cs
- TrackingProvider.cs
- TypeToken.cs
- DataGridViewDataErrorEventArgs.cs
- EncodedStreamFactory.cs
- DataSourceXmlAttributeAttribute.cs
- RoleGroupCollection.cs
- SimpleParser.cs
- FigureParagraph.cs
- BatchParser.cs
- HttpRequestCacheValidator.cs
- StrongTypingException.cs
- InternalUserCancelledException.cs
- HyperLinkDataBindingHandler.cs
- ObservableCollectionDefaultValueFactory.cs
- ServicePointManagerElement.cs
- TargetControlTypeAttribute.cs
- BlurBitmapEffect.cs
- JsonUriDataContract.cs
- OleDbPermission.cs
- DbDataAdapter.cs
- UriTemplateTrieLocation.cs
- RemoteWebConfigurationHostServer.cs
- RbTree.cs
- EntityContainerRelationshipSet.cs