Code:
/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / ProviderBase / WrappedIUnknown.cs / 1 / 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. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- ImageClickEventArgs.cs
- WindowInteractionStateTracker.cs
- DeleteMemberBinder.cs
- NonBatchDirectoryCompiler.cs
- DataRecordObjectView.cs
- UInt32Converter.cs
- MimeMapping.cs
- ToolStripPanelRow.cs
- JoinQueryOperator.cs
- EventPropertyMap.cs
- DataGridViewCellErrorTextNeededEventArgs.cs
- XmlNamedNodeMap.cs
- ZoomPercentageConverter.cs
- HyperLink.cs
- SerializationObjectManager.cs
- Registration.cs
- TreeNodeBinding.cs
- BamlResourceSerializer.cs
- ViewGenResults.cs
- DataGridColumnFloatingHeader.cs
- ReaderWriterLock.cs
- RangeValueProviderWrapper.cs
- PersistenceTypeAttribute.cs
- CroppedBitmap.cs
- OrderedDictionaryStateHelper.cs
- ITreeGenerator.cs
- MetadataConversionError.cs
- WebPartEditVerb.cs
- SspiHelper.cs
- SqlConnectionFactory.cs
- WebPartManagerInternals.cs
- ColumnMapTranslator.cs
- ScriptServiceAttribute.cs
- httpstaticobjectscollection.cs
- DataServiceQueryException.cs
- ThaiBuddhistCalendar.cs
- DelegatingConfigHost.cs
- ContentControl.cs
- MDIControlStrip.cs
- SecurityAppliedMessage.cs
- WebPartUtil.cs
- DataGridCaption.cs
- Typography.cs
- DataColumnPropertyDescriptor.cs
- NonClientArea.cs
- SamlAuthorizationDecisionClaimResource.cs
- FacetDescriptionElement.cs
- Visual3DCollection.cs
- precedingquery.cs
- NonBatchDirectoryCompiler.cs
- OleDbConnectionFactory.cs
- AddInContractAttribute.cs
- PenThreadWorker.cs
- HwndSourceKeyboardInputSite.cs
- HtmlElementCollection.cs
- KnownTypes.cs
- EventProviderWriter.cs
- FixedDocumentPaginator.cs
- BamlVersionHeader.cs
- ProjectionCamera.cs
- WebPartUserCapability.cs
- XhtmlBasicTextViewAdapter.cs
- KeysConverter.cs
- PixelShader.cs
- DataObjectPastingEventArgs.cs
- SqlGenericUtil.cs
- ShaderRenderModeValidation.cs
- XhtmlConformanceSection.cs
- EmptyImpersonationContext.cs
- EntityTypeEmitter.cs
- OleDbErrorCollection.cs
- DocumentDesigner.cs
- ISAPIRuntime.cs
- IpcPort.cs
- CustomAttributeBuilder.cs
- cookiecollection.cs
- HttpModuleCollection.cs
- SiteMapNodeItemEventArgs.cs
- SafeSecurityHandles.cs
- SmtpNtlmAuthenticationModule.cs
- UserNamePasswordValidator.cs
- WebPartEditorApplyVerb.cs
- QueryResultOp.cs
- CompatibleComparer.cs
- ByteStack.cs
- BoundingRectTracker.cs
- ConditionalBranch.cs
- DiscoveryMessageSequence11.cs
- SimpleModelProvider.cs
- SQLChars.cs
- DiscoveryDocumentSerializer.cs
- PointCollection.cs
- _SafeNetHandles.cs
- PlaceHolder.cs
- MetadataItem.cs
- ServicesUtilities.cs
- FocusTracker.cs
- TimeSpanOrInfiniteConverter.cs
- errorpatternmatcher.cs
- FlatButtonAppearance.cs