Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / ProviderBase / WrappedIUnknown.cs / 1305376 / WrappedIUnknown.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data.ProviderBase { using System; using System.Data.Common; using System.Runtime.CompilerServices; using System.Runtime.ConstrainedExecution; using System.Runtime.InteropServices; using System.Security; using System.Security.Permissions; using System.Threading; // We wrap the interface as a native IUnknown IntPtr so that every // thread that creates a connection will fake the correct context when // in transactions, otherwise everything is marshalled. We do this // for two reasons: first for the connection pooler, this is a significant // performance gain, second for the OLE DB provider, it doesn't marshal. internal class WrappedIUnknown : SafeHandle { internal WrappedIUnknown() : base(IntPtr.Zero, true) { } internal WrappedIUnknown(object unknown) : this() { if (null != unknown) { RuntimeHelpers.PrepareConstrainedRegions(); try {} finally { base.handle = Marshal.GetIUnknownForObject(unknown); // } } } public override bool IsInvalid { get { return (IntPtr.Zero == base.handle); } } internal object ComWrapper() { // NOTE: Method, instead of property, to avoid being evaluated at // runtime in the debugger. object value = null; bool mustRelease = false; RuntimeHelpers.PrepareConstrainedRegions(); try { DangerousAddRef(ref mustRelease); IntPtr handle = DangerousGetHandle(); value = System.Runtime.Remoting.Services.EnterpriseServicesHelper.WrapIUnknownWithComObject(handle); } finally { if (mustRelease) { DangerousRelease(); } } return value; } override protected bool ReleaseHandle() { // NOTE: The SafeHandle class guarantees this will be called exactly once. IntPtr ptr = base.handle; base.handle = IntPtr.Zero; if (IntPtr.Zero != ptr) { Marshal.Release(ptr); } return true; } } } // 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
- DynamicFilter.cs
- Int32.cs
- CacheAxisQuery.cs
- hresults.cs
- GenericTextProperties.cs
- TransformDescriptor.cs
- DataGridColumnCollection.cs
- HandleCollector.cs
- DragSelectionMessageFilter.cs
- TextEditorSelection.cs
- DbProviderFactories.cs
- DataGridViewSelectedColumnCollection.cs
- SafeBitVector32.cs
- GreaterThan.cs
- MenuItem.cs
- TransformerInfoCollection.cs
- QueryCacheKey.cs
- ActivitiesCollection.cs
- WebPartAddingEventArgs.cs
- DBAsyncResult.cs
- SymmetricCryptoHandle.cs
- FrameSecurityDescriptor.cs
- ISAPIRuntime.cs
- DesignTimeXamlWriter.cs
- ContainerFilterService.cs
- BitmapEffectDrawing.cs
- ObjectItemCollection.cs
- TextElementAutomationPeer.cs
- ProtocolsConfigurationEntry.cs
- XmlILStorageConverter.cs
- RegexRunner.cs
- DataBindEngine.cs
- XmlSortKeyAccumulator.cs
- SocketPermission.cs
- ResizeBehavior.cs
- EnumUnknown.cs
- BindingCollection.cs
- Row.cs
- pingexception.cs
- BCLDebug.cs
- SemaphoreFullException.cs
- FileBasedResourceGroveler.cs
- TextLineResult.cs
- PrintDialog.cs
- X509Utils.cs
- SecurityTokenException.cs
- X509RawDataKeyIdentifierClause.cs
- ConfigurationManagerInternalFactory.cs
- SqlDataSourceConfigureFilterForm.cs
- ComPlusInstanceProvider.cs
- ParameterRetriever.cs
- EnvelopedPkcs7.cs
- CodeCommentStatementCollection.cs
- LogReservationCollection.cs
- IMembershipProvider.cs
- LongValidatorAttribute.cs
- newinstructionaction.cs
- WebException.cs
- SByteStorage.cs
- XmlRootAttribute.cs
- RtfToXamlLexer.cs
- TextServicesDisplayAttribute.cs
- baseaxisquery.cs
- XpsPartBase.cs
- BamlLocalizer.cs
- LocalizationComments.cs
- ProfileSettingsCollection.cs
- ExceptionCollection.cs
- ImageListDesigner.cs
- ImageList.cs
- ExchangeUtilities.cs
- AtomPub10CategoriesDocumentFormatter.cs
- DataBinder.cs
- WriteFileContext.cs
- PeerApplication.cs
- EncoderBestFitFallback.cs
- AsyncPostBackErrorEventArgs.cs
- ResourceDisplayNameAttribute.cs
- HtmlInputFile.cs
- ImageSourceConverter.cs
- WebBrowserContainer.cs
- AsymmetricAlgorithm.cs
- PromptStyle.cs
- WinFormsComponentEditor.cs
- Dispatcher.cs
- PtsHost.cs
- BindingManagerDataErrorEventArgs.cs
- ToolStripOverflowButton.cs
- FontSizeConverter.cs
- AttachInfo.cs
- Part.cs
- UriScheme.cs
- EditorZoneBase.cs
- PolyLineSegmentFigureLogic.cs
- HttpsChannelListener.cs
- isolationinterop.cs
- ListArgumentProvider.cs
- Parser.cs
- _AutoWebProxyScriptHelper.cs
- TextProviderWrapper.cs