Code:
/ FXUpdate3074 / FXUpdate3074 / 1.1 / untmp / whidbey / QFE / ndp / clr / src / BCL / System / Globalization / AgileSafeNativeMemoryHandle.cs / 1 / AgileSafeNativeMemoryHandle.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== /*============================================================ ** ** Class: AgileSafeNativeMemoryHandle ** ** This class is to hold native memory handle and make sure it ** gets released when the object get collected by GC. ** ** This class can hold one of two types of memory handle ** first it can hold a handle for memory created using ** Marshal.AllocHGlobal. this can happen when creating ** the object using constructor taking IntPtr as handle. ** in this case mode = false. ** ** second it can hold handle for memory created from mapped ** file. this can happen when creating the object using the ** file name then the constructor will open and map this file ** and hold the mapped memory section handle ** in this case mode = true. ** ** IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT ** this class is used only with CultureInfo or its ** field classes. ** this class is special case that is agile and has finalizer ** and it is a special case like Thread class. ** this class is agile to make sure it survive the app domain ** unloading. otherwise we can get AV when culture info cross ** the app domain boundary. ** so don't use it in any other purpose. ** ===========================================================*/ using System; using System.IO; using System.Security; using System.Security.Permissions; using System.Runtime.InteropServices; using System.Runtime.CompilerServices; using System.Runtime.ConstrainedExecution; using Microsoft.Win32; using Microsoft.Win32.SafeHandles; using System.Runtime.Versioning; namespace System.Globalization { internal sealed class AgileSafeNativeMemoryHandle : SafeHandleZeroOrMinusOneIsInvalid { private const int PAGE_READONLY = 0x02; private const int SECTION_MAP_READ = 0x0004; private unsafe byte* bytes; // // The only handle we keep it open is the mapped memory section and we close // both the stream and mapped file handle as the OS keep the memory section // mapped even when closing the files. // The benefit for closing the file and stream handle is have flexability // to rename the file while it is in use. // private long fileSize = 0; // mode is true if the memory created from mapped file. // and false if the memory created from Marshal.AllocHGlobal. private bool mode = false; [SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode=true)] internal AgileSafeNativeMemoryHandle() : base(true) {} [SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode=true)] internal AgileSafeNativeMemoryHandle(IntPtr handle, bool ownsHandle) : base (ownsHandle) { SetHandle(handle); } [ResourceExposure(ResourceScope.Machine)] [ResourceConsumption(ResourceScope.Machine)] internal unsafe AgileSafeNativeMemoryHandle(String fileName) : this(fileName, null) {} [ResourceExposure(ResourceScope.Machine)] [ResourceConsumption(ResourceScope.Machine)] internal unsafe AgileSafeNativeMemoryHandle(String fileName, String fileMappingName) : base(true) { mode = true; // // Use native API to create the file directly. // SafeFileHandle fileHandle = Win32Native.UnsafeCreateFile(fileName, FileStream.GENERIC_READ, FileShare.Read, null, FileMode.Open, 0, IntPtr.Zero); int lastError = Marshal.GetLastWin32Error(); if (fileHandle.IsInvalid) { BCLDebug.Assert(false, "Failed to create file " + fileName + ", GetLastError = " + lastError); throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError)); } int highSize; int lowSize = Win32Native.GetFileSize(fileHandle, out highSize); if (lowSize == Win32Native.INVALID_FILE_SIZE) { fileHandle.Close(); BCLDebug.Assert(false, "Failed to get the file size of " + fileName + ", GetLastError = " + lastError); throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError)); } fileSize = (((long) highSize) << 32) | ((uint) lowSize); if (fileSize == 0) { // we cannot map zero size file. the caller should fileHandle.Close(); return; } SafeFileMappingHandle fileMapHandle = Win32Native.CreateFileMapping(fileHandle, IntPtr.Zero, PAGE_READONLY, 0, 0, fileMappingName); lastError = Marshal.GetLastWin32Error(); fileHandle.Close(); if (fileMapHandle.IsInvalid) { BCLDebug.Assert(false, "Failed to create file mapping for file " + fileName + ", GetLastError = " + lastError); throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError)); } // Use a CER to ensure that we store the handle within this SafeHandle without allowing async exceptions. RuntimeHelpers.PrepareConstrainedRegions(); try { } finally { handle = Win32Native.MapViewOfFile(fileMapHandle, SECTION_MAP_READ, 0, 0, UIntPtr.Zero); } lastError = Marshal.GetLastWin32Error(); if (handle == IntPtr.Zero) { fileMapHandle.Close(); BCLDebug.Assert(false, "Failed to map a view of file " + fileName + ", GetLastError = " + lastError); throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("InvalidOperation_UnexpectedWin32Error"), lastError)); } bytes = (byte*) this.DangerousGetHandle(); fileMapHandle.Close(); } internal long FileSize { get { BCLDebug.Assert(mode == true, "The memory is not created from mapped file to request the size"); return fileSize; } } internal unsafe byte* GetBytePtr() { BCLDebug.Assert(bytes != null && mode == true, "bytes can requested only if the memory created from mapped file"); return (bytes); } override protected bool ReleaseHandle() { if (!IsInvalid) { if (mode == true) { if (Win32Native.UnmapViewOfFile(handle)) { handle = IntPtr.Zero; return true; } } else { Marshal.FreeHGlobal(handle); handle = IntPtr.Zero; return true; } } return false; } } } // 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
- MetabaseReader.cs
- ColorContextHelper.cs
- UIElementAutomationPeer.cs
- InstanceDataCollectionCollection.cs
- BitSet.cs
- LineBreakRecord.cs
- StatusBarItemAutomationPeer.cs
- PeerEndPoint.cs
- MetadataSerializer.cs
- Rect.cs
- TextEvent.cs
- EnumMember.cs
- SrgsText.cs
- XmlEncoding.cs
- RawStylusInputCustomData.cs
- Identity.cs
- ResXDataNode.cs
- RawTextInputReport.cs
- EdmComplexTypeAttribute.cs
- GridViewRowEventArgs.cs
- WebConvert.cs
- GlyphInfoList.cs
- LogLogRecordEnumerator.cs
- EnumValidator.cs
- RedirectionProxy.cs
- ConnectionsZone.cs
- ReadContentAsBinaryHelper.cs
- X509Certificate.cs
- Scalars.cs
- WindowsFormsSynchronizationContext.cs
- QuaternionIndependentAnimationStorage.cs
- webeventbuffer.cs
- SafeHGlobalHandleCritical.cs
- FixUpCollection.cs
- SqlDataRecord.cs
- ReliableMessagingVersionConverter.cs
- XmlCollation.cs
- _Connection.cs
- FormViewCommandEventArgs.cs
- ObjectIDGenerator.cs
- FixedSOMSemanticBox.cs
- PointLight.cs
- BaseHashHelper.cs
- COM2ExtendedUITypeEditor.cs
- FontNamesConverter.cs
- FontConverter.cs
- Int32CollectionValueSerializer.cs
- HTTPNotFoundHandler.cs
- UpdateManifestForBrowserApplication.cs
- XmlUtf8RawTextWriter.cs
- MergeFilterQuery.cs
- CollaborationHelperFunctions.cs
- BindingCompleteEventArgs.cs
- DataGridViewRowErrorTextNeededEventArgs.cs
- CountdownEvent.cs
- JulianCalendar.cs
- ElementUtil.cs
- OrderedDictionaryStateHelper.cs
- Domain.cs
- TextFormatterImp.cs
- ParameterModifier.cs
- BoundColumn.cs
- ExpressionHelper.cs
- EditorZoneDesigner.cs
- CacheEntry.cs
- SchemaImporter.cs
- OdbcConnectionHandle.cs
- SimpleTextLine.cs
- BitmapDecoder.cs
- ITreeGenerator.cs
- SQLDecimal.cs
- TableRowCollection.cs
- DesignTimeTemplateParser.cs
- DefaultTypeArgumentAttribute.cs
- AccessibleObject.cs
- WebBrowserNavigatedEventHandler.cs
- CompoundFileIOPermission.cs
- SaveWorkflowAsyncResult.cs
- CustomAttributeSerializer.cs
- ConfigXmlDocument.cs
- GridEntryCollection.cs
- ErrorHandlingAcceptor.cs
- TabControlAutomationPeer.cs
- RoleManagerSection.cs
- PanelStyle.cs
- SqlWorkflowPersistenceService.cs
- StylusButtonCollection.cs
- ValidationError.cs
- SchemaCollectionPreprocessor.cs
- MonthCalendarDesigner.cs
- ResourceReferenceExpressionConverter.cs
- FlowDocumentFormatter.cs
- XXXOnTypeBuilderInstantiation.cs
- NonBatchDirectoryCompiler.cs
- DataGridColumnHeader.cs
- RectangleConverter.cs
- FirstMatchCodeGroup.cs
- PageThemeCodeDomTreeGenerator.cs
- ProtocolsConfigurationHandler.cs
- SerializationInfoEnumerator.cs