Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / OleDb / SafeHandles.cs / 1305376 / SafeHandles.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data.OleDb { using System; using System.Data.Common; using System.Data.ProviderBase; using System.Diagnostics; using System.Globalization; using System.Runtime.CompilerServices; using System.Runtime.InteropServices; using System.Security; using System.Security.Permissions; using System.Threading; using System.Runtime.ConstrainedExecution; internal sealed class DualCoTaskMem : SafeHandle { private IntPtr handle2; // this must be protected so derived classes can use out params. private DualCoTaskMem() : base(IntPtr.Zero, true) { this.handle2 = IntPtr.Zero; } // IDBInfo.GetLiteralInfo internal DualCoTaskMem(UnsafeNativeMethods.IDBInfo dbInfo, int[] literals, out int literalCount, out IntPtr literalInfo, out OleDbHResult hr) : this() { int count = (null != literals) ? literals.Length : 0; Bid.Trace("\n"); hr = dbInfo.GetLiteralInfo(count, literals, out literalCount, out base.handle, out this.handle2); literalInfo = base.handle; Bid.Trace(" %08X{HRESULT}\n", hr); } // IColumnsInfo.GetColumnInfo internal DualCoTaskMem(UnsafeNativeMethods.IColumnsInfo columnsInfo, out IntPtr columnCount, out IntPtr columnInfos, out OleDbHResult hr) : this() { Bid.Trace(" \n"); hr = columnsInfo.GetColumnInfo(out columnCount, out base.handle, out this.handle2); columnInfos = base.handle; Bid.Trace(" %08X{HRESULT}\n", hr); } // IDBSchemaRowset.GetSchemas internal DualCoTaskMem(UnsafeNativeMethods.IDBSchemaRowset dbSchemaRowset, out int schemaCount, out IntPtr schemaGuids, out IntPtr schemaRestrictions, out OleDbHResult hr) : this() { Bid.Trace(" \n"); hr = dbSchemaRowset.GetSchemas(out schemaCount, out base.handle, out this.handle2); schemaGuids = base.handle; schemaRestrictions = this.handle2; Bid.Trace(" %08X{HRESULT}\n", hr); } internal DualCoTaskMem(UnsafeNativeMethods.IColumnsRowset icolumnsRowset, out IntPtr cOptColumns, out OleDbHResult hr) : base(IntPtr.Zero, true) { Bid.Trace(" \n"); hr = icolumnsRowset.GetAvailableColumns(out cOptColumns, out base.handle); Bid.Trace(" %08X{HRESULT}\n", hr); } public override bool IsInvalid { get { return (((IntPtr.Zero == base.handle)) && (IntPtr.Zero == this.handle2)); } } protected override 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) { SafeNativeMethods.CoTaskMemFree(ptr); } ptr = this.handle2; this.handle2 = IntPtr.Zero; if (IntPtr.Zero != ptr) { SafeNativeMethods.CoTaskMemFree(ptr); } return true; } } internal sealed class RowHandleBuffer : DbBuffer { internal RowHandleBuffer(IntPtr rowHandleFetchCount) : base((int)rowHandleFetchCount*ADP.PtrSize) { } internal IntPtr GetRowHandle(int index) { IntPtr value = ReadIntPtr( index * ADP.PtrSize); Debug.Assert(ODB.DB_NULL_HROW != value, "bad rowHandle"); return value; } } internal sealed class StringMemHandle : DbBuffer { internal StringMemHandle(string value) : base((null != value) ? checked(2+2*value.Length) : 0) { if (null != value) { // null-termination exists because of the extra 2+ which is zero'd during on allocation WriteCharArray(0, value.ToCharArray(), 0, value.Length); } } } internal sealed class ChapterHandle : WrappedIUnknown { internal static readonly ChapterHandle DB_NULL_HCHAPTER = new ChapterHandle(IntPtr.Zero); private IntPtr _chapterHandle; internal static ChapterHandle CreateChapterHandle(object chapteredRowset, RowBinding binding, int valueOffset) { if ((null == chapteredRowset) || (IntPtr.Zero == binding.ReadIntPtr(valueOffset))) { return ChapterHandle.DB_NULL_HCHAPTER; } return new ChapterHandle(chapteredRowset, binding, valueOffset); } // from ADODBRecordSetConstruction we do not want to release the initial chapter handle internal static ChapterHandle CreateChapterHandle(IntPtr chapter) { if (IntPtr.Zero == chapter) { return ChapterHandle.DB_NULL_HCHAPTER; } return new ChapterHandle(chapter); } // from ADODBRecordSetConstruction we do not want to release the initial chapter handle private ChapterHandle(IntPtr chapter) : base((object)null) { _chapterHandle = chapter; } private ChapterHandle(object chapteredRowset, RowBinding binding, int valueOffset) : base(chapteredRowset) { RuntimeHelpers.PrepareConstrainedRegions(); try {} finally { _chapterHandle = binding.InterlockedExchangePointer(valueOffset); } } internal IntPtr HChapter { get { return _chapterHandle; } } protected override bool ReleaseHandle() { // NOTE: The SafeHandle class guarantees this will be called exactly once and is non-interrutible. IntPtr chapter = _chapterHandle; _chapterHandle = IntPtr.Zero; if ((IntPtr.Zero != base.handle) && (IntPtr.Zero != chapter)) { Bid.Trace(" Chapter=%Id\n", chapter); OleDbHResult hr = (OleDbHResult)NativeOledbWrapper.IChapteredRowsetReleaseChapter(base.handle, chapter); Bid.Trace(" %08X{HRESULT}\n", hr); } return base.ReleaseHandle(); } } } // 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
- ArgumentValidation.cs
- RawStylusInputCustomDataList.cs
- ControlIdConverter.cs
- PropertyCollection.cs
- InvokeProviderWrapper.cs
- PixelShader.cs
- SQLInt64Storage.cs
- EntityClientCacheKey.cs
- WsatServiceCertificate.cs
- _DigestClient.cs
- XmlElementAttribute.cs
- XmlSchemaAppInfo.cs
- COM2DataTypeToManagedDataTypeConverter.cs
- OdbcConnectionOpen.cs
- HotSpotCollection.cs
- PropertyCollection.cs
- XmlElementCollection.cs
- XamlWriter.cs
- ReadOnlyHierarchicalDataSourceView.cs
- SrgsElement.cs
- DisposableCollectionWrapper.cs
- BatchServiceHost.cs
- ToolStripCodeDomSerializer.cs
- BaseValidatorDesigner.cs
- CharStorage.cs
- EmptyEnumerator.cs
- FixedBufferAttribute.cs
- Win32KeyboardDevice.cs
- FormatException.cs
- Menu.cs
- BinaryReader.cs
- ISSmlParser.cs
- SettingsContext.cs
- PrintDialog.cs
- TypeValidationEventArgs.cs
- EastAsianLunisolarCalendar.cs
- ElementUtil.cs
- RoleGroupCollectionEditor.cs
- DataGridAddNewRow.cs
- SoapMessage.cs
- RequiredFieldValidator.cs
- FlowDocument.cs
- EntityObject.cs
- Italic.cs
- SQLDecimalStorage.cs
- ToolStripHighContrastRenderer.cs
- DataListItemEventArgs.cs
- PersonalizableAttribute.cs
- KeyedHashAlgorithm.cs
- DaylightTime.cs
- FrugalMap.cs
- Int32AnimationUsingKeyFrames.cs
- Geometry3D.cs
- RuntimeWrappedException.cs
- _Semaphore.cs
- CompModSwitches.cs
- UmAlQuraCalendar.cs
- OutputCacheSettingsSection.cs
- StandardTransformFactory.cs
- SystemException.cs
- MessagingDescriptionAttribute.cs
- ConnectionPointCookie.cs
- RotateTransform.cs
- PropertyNames.cs
- BitmapEffectState.cs
- SqlMethodCallConverter.cs
- DbSource.cs
- DataBindingHandlerAttribute.cs
- StateChangeEvent.cs
- JoinGraph.cs
- ProfessionalColorTable.cs
- Encoder.cs
- Char.cs
- MSAANativeProvider.cs
- Clock.cs
- GiveFeedbackEventArgs.cs
- ErrorLog.cs
- ObjectTag.cs
- MatchAllMessageFilter.cs
- VisualStyleElement.cs
- HttpHandlersSection.cs
- ListItemsCollectionEditor.cs
- HttpListenerException.cs
- ParameterCollection.cs
- AttachedPropertyBrowsableAttribute.cs
- GridSplitterAutomationPeer.cs
- ProtocolViolationException.cs
- DBSqlParserTableCollection.cs
- storagemappingitemcollection.viewdictionary.cs
- IntellisenseTextBox.designer.cs
- ColumnResizeAdorner.cs
- ScriptingJsonSerializationSection.cs
- SafeNativeMethods.cs
- SystemColors.cs
- CatalogPartCollection.cs
- WebPermission.cs
- LongCountAggregationOperator.cs
- MachineKeySection.cs
- AllowedAudienceUriElement.cs
- FreezableDefaultValueFactory.cs