Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / Threading / HostExecutionContextManager.cs / 1305376 / HostExecutionContextManager.cs
using System.Diagnostics.Contracts; // ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // //[....] /*============================================================ ** ** Class: ExecutionContext ** ** ** Purpose: Capture Host execution context for a thread ** ** ===========================================================*/ namespace System.Threading { using System.Security; using System.Runtime.Remoting; using System.Runtime.CompilerServices; using System.Runtime.Serialization; using System.Security.Permissions; using System.Runtime.Remoting.Messaging; using System.Runtime.ConstrainedExecution; using System.Runtime.Versioning; using System.Runtime.InteropServices; internal class HostExecutionContextSwitcher { internal ExecutionContext executionContext; internal HostExecutionContext previousHostContext; internal HostExecutionContext currentHostContext; [System.Security.SecurityCritical] // auto-generated [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)] static public void Undo(Object switcherObject) { if (switcherObject == null) return; // otherwise call the host HostExecutionContextManager hostMgr = HostExecutionContextManager.GetCurrentHostExecutionContextManager(); if (hostMgr != null) { hostMgr.Revert(switcherObject); } } } public class HostExecutionContext : IDisposable { private Object state; protected internal Object State { get { return state; } set { state = value; } } public HostExecutionContext() { } public HostExecutionContext(Object state) { this.state = state; } [System.Security.SecuritySafeCritical] // auto-generated public virtual HostExecutionContext CreateCopy() { Object newState = state; if (state is IUnknownSafeHandle) { // Clone the IUnknown handle newState = ((IUnknownSafeHandle)state).Clone(); } return new HostExecutionContext(state); } public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } public virtual void Dispose(bool disposing) { return; } } [System.Security.SecurityCritical] // auto-generated internal class IUnknownSafeHandle : SafeHandle { public IUnknownSafeHandle() : base(IntPtr.Zero, true) { } public override bool IsInvalid { [System.Security.SecurityCritical] get { return handle == IntPtr.Zero; } } [System.Security.SecurityCritical] override protected bool ReleaseHandle() { HostExecutionContextManager.ReleaseHostSecurityContext(this.handle); return true; } internal Object Clone() { IUnknownSafeHandle unkSafeHandleCloned = new IUnknownSafeHandle(); // call into the Hosting API to CLONE the host context // stores the output IUnknown in the safehandle, if (!IsInvalid) { HostExecutionContextManager.CloneHostSecurityContext(this, unkSafeHandleCloned); } return unkSafeHandleCloned; } } public class HostExecutionContextManager { private static bool _fIsHostedChecked; private static bool _fIsHosted; private static HostExecutionContextManager _hostExecutionContextManager; [System.Security.SecurityCritical] // auto-generated [ResourceExposure(ResourceScope.None)] [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)] [MethodImplAttribute(MethodImplOptions.InternalCall)] static private extern bool HostSecurityManagerPresent(); [System.Security.SecurityCritical] // auto-generated [ResourceExposure(ResourceScope.None)] [MethodImplAttribute(MethodImplOptions.InternalCall)] static internal extern int ReleaseHostSecurityContext(IntPtr context); [System.Security.SecurityCritical] // auto-generated [ResourceExposure(ResourceScope.None)] [MethodImplAttribute(MethodImplOptions.InternalCall)] static internal extern int CloneHostSecurityContext(SafeHandle context, SafeHandle clonedContext); [System.Security.SecurityCritical] // auto-generated [ResourceExposure(ResourceScope.None)] [MethodImplAttribute(MethodImplOptions.InternalCall)] static private extern int CaptureHostSecurityContext(SafeHandle capturedContext); [System.Security.SecurityCritical] // auto-generated [ResourceExposure(ResourceScope.None)] [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)] [MethodImplAttribute(MethodImplOptions.InternalCall)] static private extern int SetHostSecurityContext(SafeHandle context, bool fReturnPrevious, SafeHandle prevContext); [System.Security.SecurityCritical] // auto-generated internal static bool CheckIfHosted() { if (!_fIsHostedChecked) { _fIsHosted = HostSecurityManagerPresent(); _fIsHostedChecked = true; } return _fIsHosted; } // capture Host SecurityContext [System.Security.SecuritySafeCritical] // auto-generated public virtual HostExecutionContext Capture() { HostExecutionContext context = null; // check if we are hosted if (CheckIfHosted()) { IUnknownSafeHandle unkSafeHandle = new IUnknownSafeHandle(); context = new HostExecutionContext(unkSafeHandle); // call into the Hosting API to capture the host context // stores the output IUnknown in the safehandle, CaptureHostSecurityContext(unkSafeHandle); } // otherwise return context; } // Set Host SecurityContext [System.Security.SecurityCritical] // auto-generated_required public virtual Object SetHostExecutionContext(HostExecutionContext hostExecutionContext) { if (hostExecutionContext == null) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_NotNewCaptureContext")); } Contract.EndContractBlock(); HostExecutionContextSwitcher switcher = new HostExecutionContextSwitcher(); ExecutionContext currentExecutionContext = Thread.CurrentThread.ExecutionContext; switcher.executionContext = currentExecutionContext; switcher.currentHostContext = hostExecutionContext; switcher.previousHostContext = null; if (CheckIfHosted()) { if (hostExecutionContext.State is IUnknownSafeHandle) { // setup the previous unknown handle IUnknownSafeHandle unkPrevSafeHandle = new IUnknownSafeHandle(); switcher.previousHostContext = new HostExecutionContext(unkPrevSafeHandle); // get the current handle IUnknownSafeHandle unkSafeHandle = (IUnknownSafeHandle)hostExecutionContext.State; // call into the Hosting API to set the host context // second arg indicates whether we want to retrieve the previous context SetHostSecurityContext(unkSafeHandle,true,unkPrevSafeHandle); } } // store the current HostExecutionContext in the ExecutionContext. currentExecutionContext.HostExecutionContext = hostExecutionContext; return switcher; } // this method needs to be reliable [System.Security.SecurityCritical] // auto-generated_required [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)] public virtual void Revert(Object previousState) { HostExecutionContextSwitcher hostContextSwitcher = previousState as HostExecutionContextSwitcher; if (hostContextSwitcher == null) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotOverrideSetWithoutRevert")); } // check Undo is happening on the correct thread ExecutionContext executionContext = Thread.CurrentThread.ExecutionContext; if (executionContext != hostContextSwitcher.executionContext) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotUseSwitcherOtherThread")); } hostContextSwitcher.executionContext = null; // Make sure switcher cannot be re-used. HostExecutionContext revertFromHostContext = executionContext.HostExecutionContext; // if the current host context is not the same as the one in the switcher, then revert is being called out of order if (revertFromHostContext != hostContextSwitcher.currentHostContext) { throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotUseSwitcherOtherThread")); } // get the previous host context HostExecutionContext revertToHostContext = hostContextSwitcher.previousHostContext; // now check if we are hosted and revert the context in the host if (CheckIfHosted()) { // try restore the previous context as the current context if (revertToHostContext != null && revertToHostContext.State is IUnknownSafeHandle) { IUnknownSafeHandle unkprevSafeHandle = (IUnknownSafeHandle)revertToHostContext.State; // call into the Hosting API to set the host context SetHostSecurityContext(unkprevSafeHandle, false, null); } } //restore the previous host context in the executioncontext executionContext.HostExecutionContext = revertToHostContext; } [System.Security.SecurityCritical] // auto-generated internal static HostExecutionContext CaptureHostExecutionContext() { HostExecutionContext hostContext = null; // capture the host execution context HostExecutionContextManager hostMgr = HostExecutionContextManager.GetCurrentHostExecutionContextManager(); if (hostMgr != null) { hostContext = hostMgr.Capture(); } return hostContext; } [System.Security.SecurityCritical] // auto-generated internal static Object SetHostExecutionContextInternal(HostExecutionContext hostContext) { HostExecutionContextManager hostMgr = HostExecutionContextManager.GetCurrentHostExecutionContextManager(); Object switcher = null; if (hostMgr != null) { switcher = hostMgr.SetHostExecutionContext(hostContext); // } return switcher; } // retun the HostExecutionContextManager for the current AppDomain [System.Security.SecurityCritical] // auto-generated [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)] internal static HostExecutionContextManager GetCurrentHostExecutionContextManager() { // this is called during AppDomainManager initialization, this is a thread safe place // to setup the HostExecutionContextManager for the current AppDomain if (AppDomainManager.CurrentAppDomainManager != null) { return AppDomainManager.CurrentAppDomainManager.HostExecutionContextManager; } return null; } // retun the HostExecutionContextManager for the current AppDomain internal static HostExecutionContextManager GetInternalHostExecutionContextManager() { if (_hostExecutionContextManager == null) { // setup the HostExecutionContextManager for the current AppDomain Contract.Assert(_hostExecutionContextManager == null, "HostExecutionContextManager should be null"); _hostExecutionContextManager = new HostExecutionContextManager(); } return _hostExecutionContextManager; } } } // 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
- ImageCodecInfoPrivate.cs
- IListConverters.cs
- XmlLoader.cs
- HtmlDocument.cs
- ListBox.cs
- XPathNodeHelper.cs
- PersonalizationProviderHelper.cs
- StrokeCollectionDefaultValueFactory.cs
- ListViewContainer.cs
- WindowsHyperlink.cs
- OdbcErrorCollection.cs
- Floater.cs
- MissingManifestResourceException.cs
- WorkflowInstance.cs
- PropertyOrder.cs
- BitmapEffect.cs
- QueuePropertyVariants.cs
- StorageComplexPropertyMapping.cs
- SqlReorderer.cs
- CommandEventArgs.cs
- CustomTypeDescriptor.cs
- BuildManager.cs
- ResXFileRef.cs
- BinaryFormatterWriter.cs
- DependencyObject.cs
- XmlSchemaAny.cs
- CommandID.cs
- GeneralTransform2DTo3DTo2D.cs
- DocumentViewerAutomationPeer.cs
- XmlSchemaSet.cs
- FillBehavior.cs
- CompilationLock.cs
- Panel.cs
- RoleGroupCollection.cs
- DataGrid.cs
- SchemeSettingElement.cs
- Method.cs
- XmlTextWriter.cs
- OleDbDataReader.cs
- Calendar.cs
- TypeSystemHelpers.cs
- WebBrowserNavigatingEventHandler.cs
- WebReferencesBuildProvider.cs
- CompareValidator.cs
- MailHeaderInfo.cs
- Material.cs
- OrthographicCamera.cs
- PeekCompletedEventArgs.cs
- ModelVisual3D.cs
- ByteStreamMessageEncoderFactory.cs
- DependencyPropertyHelper.cs
- WhiteSpaceTrimStringConverter.cs
- TiffBitmapEncoder.cs
- SendMailErrorEventArgs.cs
- HTTPNotFoundHandler.cs
- UserControlParser.cs
- ColumnHeaderConverter.cs
- DispatcherHookEventArgs.cs
- SqlInternalConnection.cs
- GeneralTransformGroup.cs
- HandlerFactoryWrapper.cs
- DataGridColumnEventArgs.cs
- VisualTreeHelper.cs
- PeerNameResolver.cs
- Timer.cs
- XmlCodeExporter.cs
- OverrideMode.cs
- ServiceHttpModule.cs
- Int16Storage.cs
- ControlAdapter.cs
- BindingCompleteEventArgs.cs
- DynamicControlParameter.cs
- TextServicesLoader.cs
- COM2Properties.cs
- safex509handles.cs
- HelpProvider.cs
- AutomationPeer.cs
- ToolStripHighContrastRenderer.cs
- PriorityQueue.cs
- WebResourceAttribute.cs
- IntSecurity.cs
- WinEventTracker.cs
- SystemIPGlobalProperties.cs
- TabControlCancelEvent.cs
- ConvertBinder.cs
- MenuCommand.cs
- MergeLocalizationDirectives.cs
- Base64Encoder.cs
- ComponentDispatcher.cs
- ObjectItemCollection.cs
- IIS7UserPrincipal.cs
- SpecialNameAttribute.cs
- DbProviderConfigurationHandler.cs
- VisualStyleElement.cs
- KeyMatchBuilder.cs
- httpserverutility.cs
- HttpListenerContext.cs
- namescope.cs
- VersionedStreamOwner.cs
- ExecutionContext.cs