Code:
/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / Orcas / SP / wpf / src / UIAutomation / UIAutomationClient / MS / Internal / Automation / QueueProcessor.cs / 1 / QueueProcessor.cs
//---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // // Description: Class to create a queue on its own thread. // // History: // 06/17/2003 : BrendanM Ported to WCP // //--------------------------------------------------------------------------- // PRESHARP: In order to avoid generating warnings about unkown message numbers and unknown pragmas. #pragma warning disable 1634, 1691 using System.Windows.Automation; using System.Windows.Automation.Provider; using System; using System.Threading; using System.Collections; using System.Diagnostics; using MS.Internal.Automation; using MS.Win32; using System.Runtime.InteropServices; using Microsoft.Win32.SafeHandles; namespace MS.Internal.Automation { // Abstract class for worker objects queued to the QueueProcessor class internal abstract class QueueItem { internal abstract void Process(); } // Class to create a queue on its own thread. Used on the PAW client-side // to queue client callbacks. This prevents a deadlock situation when the // client calls back into PAW from w/in a callback. All events are queued // through this class. internal class QueueProcessor { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors // Usage is create QueueProcessor object and call StartOnThread internal QueueProcessor(int initCapacity) { _ev = new AutoResetEvent(false); _q = Queue.Synchronized(new Queue(initCapacity)); } internal QueueProcessor() : this(4) { } #endregion Constructors //------------------------------------------------------ // // Internal Methods // //----------------------------------------------------- #region Internal Methods internal void StartOnThread() { _quitting = false; // create and start a background thread for this worker window to run on // (background threads will exit if the main and foreground threads exit) ThreadStart threadStart = new ThreadStart(WaitForWork); _thread = new Thread(threadStart); _thread.IsBackground = true; _thread.Start(); } // Post a work item to the queue (from another thread) internal bool PostWorkItem(QueueItem workItem) { Debug.Assert(!_quitting, "Can't add items to queue when quitting"); _q.Enqueue(workItem); _ev.Set(); return true; } // Post a work item and wait for it to be processed // Return true if the item was processed w/in 2 sec else false internal bool PostSyncWorkItem(QueueItem workItem) { Debug.Assert(!_quitting, "Can't add items to queue when quitting"); SyncQueueItem syncItem = new SyncQueueItem(workItem); _q.Enqueue(syncItem); _ev.Set(); return syncItem._ev.WaitOne(2000, false); } // Stop queuing and clean up (from another thread) internal void PostQuit() { _quitting = true; _ev.Set(); } #endregion Internal Methods //------------------------------------------------------ // // Private Methods // //------------------------------------------------------ #region Private Methods // The loop the thread uses to wait for queue items to process private void WaitForWork() { SafeWaitHandle handle = _ev.SafeWaitHandle; UnsafeNativeMethods.MSG msg = new UnsafeNativeMethods.MSG(); while (!_quitting) { // pump any messages while (UnsafeNativeMethods.PeekMessage(ref msg, NativeMethods.HWND.NULL, 0, 0, UnsafeNativeMethods.PM_REMOVE)) { if (msg.message == UnsafeNativeMethods.WM_QUIT) { break; } // From the Windows SDK documentation: // The return value specifies the value returned by the window procedure. // Although its meaning depends on the message being dispatched, the return // value generally is ignored. #pragma warning suppress 6031, 6523 UnsafeNativeMethods.DispatchMessage(ref msg); } // do any work items in the queue DrainQueue(); int lastWin32Error = 0; int result = Misc.TryMsgWaitForMultipleObjects(handle, false, UnsafeNativeMethods.INFINITE, UnsafeNativeMethods.QS_ALLINPUT, ref lastWin32Error); if (result == UnsafeNativeMethods.WAIT_FAILED || result == UnsafeNativeMethods.WAIT_TIMEOUT) { DrainQueue(); Debug.Assert(_quitting, "MsgWaitForMultipleObjects failed while WaitForWork"); break; } } DrainQueue(); } private void DrainQueue() { // It's possible items could be enqueued between when we check for the count // and dequeue but the event is set then and we'll come back into DrainQueue. // (note: don't use a for loop here because as the counter is incremented // Count is decremented and we'll only process half the queue) while (_q.Count > 0) { // pull an item off the queue, process, then clear it QueueItem item = (QueueItem)_q.Dequeue(); if (! _quitting) { try { item.Process(); } catch (Exception e) { if (Misc.IsCriticalException(e)) throw; // Eat it. // There's no place to let this exception percolate out // to so we'll stop it here. } } } } #endregion Private Methods //----------------------------------------------------- // // Private Fields // //------------------------------------------------------ #region Private Fields Thread _thread; // the thread on which QueueItem's are processed private Queue _q; // a synchronized queue private AutoResetEvent _ev; // notifies when new queue items show up private bool _quitting; // true if need to stop queueing #endregion Private Fields } // Class is used only by QueueProcessor class itself - wraps // another QueueItem, and fires an event when it is complete. internal class SyncQueueItem : QueueItem { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors internal SyncQueueItem(QueueItem qItem) { _ev = new AutoResetEvent(false); _qItem = qItem; } #endregion Constructors //----------------------------------------------------- // // Internal Methods // //------------------------------------------------------ #region Internal Methods internal override void Process() { _qItem.Process(); _ev.Set(); } #endregion Internal Methods //----------------------------------------------------- // // Private Fields // //------------------------------------------------------ #region Private Fields // Not many of these will be created at a time so having the // event in the class is OK and easier than having just one // that manages any [....] method call. internal AutoResetEvent _ev; private QueueItem _qItem; #endregion Private Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // // Description: Class to create a queue on its own thread. // // History: // 06/17/2003 : BrendanM Ported to WCP // //--------------------------------------------------------------------------- // PRESHARP: In order to avoid generating warnings about unkown message numbers and unknown pragmas. #pragma warning disable 1634, 1691 using System.Windows.Automation; using System.Windows.Automation.Provider; using System; using System.Threading; using System.Collections; using System.Diagnostics; using MS.Internal.Automation; using MS.Win32; using System.Runtime.InteropServices; using Microsoft.Win32.SafeHandles; namespace MS.Internal.Automation { // Abstract class for worker objects queued to the QueueProcessor class internal abstract class QueueItem { internal abstract void Process(); } // Class to create a queue on its own thread. Used on the PAW client-side // to queue client callbacks. This prevents a deadlock situation when the // client calls back into PAW from w/in a callback. All events are queued // through this class. internal class QueueProcessor { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors // Usage is create QueueProcessor object and call StartOnThread internal QueueProcessor(int initCapacity) { _ev = new AutoResetEvent(false); _q = Queue.Synchronized(new Queue(initCapacity)); } internal QueueProcessor() : this(4) { } #endregion Constructors //------------------------------------------------------ // // Internal Methods // //----------------------------------------------------- #region Internal Methods internal void StartOnThread() { _quitting = false; // create and start a background thread for this worker window to run on // (background threads will exit if the main and foreground threads exit) ThreadStart threadStart = new ThreadStart(WaitForWork); _thread = new Thread(threadStart); _thread.IsBackground = true; _thread.Start(); } // Post a work item to the queue (from another thread) internal bool PostWorkItem(QueueItem workItem) { Debug.Assert(!_quitting, "Can't add items to queue when quitting"); _q.Enqueue(workItem); _ev.Set(); return true; } // Post a work item and wait for it to be processed // Return true if the item was processed w/in 2 sec else false internal bool PostSyncWorkItem(QueueItem workItem) { Debug.Assert(!_quitting, "Can't add items to queue when quitting"); SyncQueueItem syncItem = new SyncQueueItem(workItem); _q.Enqueue(syncItem); _ev.Set(); return syncItem._ev.WaitOne(2000, false); } // Stop queuing and clean up (from another thread) internal void PostQuit() { _quitting = true; _ev.Set(); } #endregion Internal Methods //------------------------------------------------------ // // Private Methods // //------------------------------------------------------ #region Private Methods // The loop the thread uses to wait for queue items to process private void WaitForWork() { SafeWaitHandle handle = _ev.SafeWaitHandle; UnsafeNativeMethods.MSG msg = new UnsafeNativeMethods.MSG(); while (!_quitting) { // pump any messages while (UnsafeNativeMethods.PeekMessage(ref msg, NativeMethods.HWND.NULL, 0, 0, UnsafeNativeMethods.PM_REMOVE)) { if (msg.message == UnsafeNativeMethods.WM_QUIT) { break; } // From the Windows SDK documentation: // The return value specifies the value returned by the window procedure. // Although its meaning depends on the message being dispatched, the return // value generally is ignored. #pragma warning suppress 6031, 6523 UnsafeNativeMethods.DispatchMessage(ref msg); } // do any work items in the queue DrainQueue(); int lastWin32Error = 0; int result = Misc.TryMsgWaitForMultipleObjects(handle, false, UnsafeNativeMethods.INFINITE, UnsafeNativeMethods.QS_ALLINPUT, ref lastWin32Error); if (result == UnsafeNativeMethods.WAIT_FAILED || result == UnsafeNativeMethods.WAIT_TIMEOUT) { DrainQueue(); Debug.Assert(_quitting, "MsgWaitForMultipleObjects failed while WaitForWork"); break; } } DrainQueue(); } private void DrainQueue() { // It's possible items could be enqueued between when we check for the count // and dequeue but the event is set then and we'll come back into DrainQueue. // (note: don't use a for loop here because as the counter is incremented // Count is decremented and we'll only process half the queue) while (_q.Count > 0) { // pull an item off the queue, process, then clear it QueueItem item = (QueueItem)_q.Dequeue(); if (! _quitting) { try { item.Process(); } catch (Exception e) { if (Misc.IsCriticalException(e)) throw; // Eat it. // There's no place to let this exception percolate out // to so we'll stop it here. } } } } #endregion Private Methods //----------------------------------------------------- // // Private Fields // //------------------------------------------------------ #region Private Fields Thread _thread; // the thread on which QueueItem's are processed private Queue _q; // a synchronized queue private AutoResetEvent _ev; // notifies when new queue items show up private bool _quitting; // true if need to stop queueing #endregion Private Fields } // Class is used only by QueueProcessor class itself - wraps // another QueueItem, and fires an event when it is complete. internal class SyncQueueItem : QueueItem { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors internal SyncQueueItem(QueueItem qItem) { _ev = new AutoResetEvent(false); _qItem = qItem; } #endregion Constructors //----------------------------------------------------- // // Internal Methods // //------------------------------------------------------ #region Internal Methods internal override void Process() { _qItem.Process(); _ev.Set(); } #endregion Internal Methods //----------------------------------------------------- // // Private Fields // //------------------------------------------------------ #region Private Fields // Not many of these will be created at a time so having the // event in the class is OK and easier than having just one // that manages any [....] method call. internal AutoResetEvent _ev; private QueueItem _qItem; #endregion Private Fields } } // 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
- LambdaCompiler.Statements.cs
- LocatorGroup.cs
- NullRuntimeConfig.cs
- ThicknessAnimationUsingKeyFrames.cs
- OleServicesContext.cs
- ToolStripProfessionalLowResolutionRenderer.cs
- Expression.cs
- RootNamespaceAttribute.cs
- RenderTargetBitmap.cs
- LicenseContext.cs
- AssemblyNameProxy.cs
- autovalidator.cs
- linebase.cs
- TraceLog.cs
- SimpleHandlerFactory.cs
- HiddenFieldPageStatePersister.cs
- ProtocolsConfigurationHandler.cs
- NetworkCredential.cs
- SQLSingle.cs
- ZipIOLocalFileDataDescriptor.cs
- PointAnimationClockResource.cs
- PropertyDescriptors.cs
- ConfigurationStrings.cs
- Win32Interop.cs
- WebPartConnectionsDisconnectVerb.cs
- DocumentGrid.cs
- InProcStateClientManager.cs
- HtmlEncodedRawTextWriter.cs
- CompileLiteralTextParser.cs
- TableLayout.cs
- InternalConfigRoot.cs
- SharedStream.cs
- XmlTextAttribute.cs
- HtmlTableCell.cs
- DispatcherOperation.cs
- TypeConverterAttribute.cs
- CodeMethodInvokeExpression.cs
- NumberEdit.cs
- Track.cs
- DmlSqlGenerator.cs
- HashHelper.cs
- ZipIOModeEnforcingStream.cs
- BevelBitmapEffect.cs
- GridViewRowCollection.cs
- ActivityExecutorSurrogate.cs
- RegularExpressionValidator.cs
- SecurityKeyIdentifier.cs
- TextEditor.cs
- CrossSiteScriptingValidation.cs
- RepeaterItemCollection.cs
- PixelShader.cs
- Triangle.cs
- OledbConnectionStringbuilder.cs
- ProfileInfo.cs
- XmlNamespaceMapping.cs
- DispatchWrapper.cs
- datacache.cs
- DesigntimeLicenseContextSerializer.cs
- HttpContextServiceHost.cs
- DataGridViewColumnHeaderCell.cs
- WebPart.cs
- RegularExpressionValidator.cs
- Pen.cs
- WorkflowMarkupSerializationProvider.cs
- WebPartConnection.cs
- AssemblyName.cs
- ITextView.cs
- Soap12FormatExtensions.cs
- Invariant.cs
- AttributeEmitter.cs
- BaseCollection.cs
- ServiceOperationInvoker.cs
- MonitoringDescriptionAttribute.cs
- DataControlPagerLinkButton.cs
- ScriptResourceHandler.cs
- Error.cs
- Pair.cs
- HtmlTitle.cs
- WindowsFormsSectionHandler.cs
- HttpModuleActionCollection.cs
- DiffuseMaterial.cs
- ResourceDescriptionAttribute.cs
- DataSourceSelectArguments.cs
- HttpListenerRequestUriBuilder.cs
- CodeTypeDeclaration.cs
- Ref.cs
- LocatorGroup.cs
- CodeLinePragma.cs
- Mutex.cs
- AlignmentYValidation.cs
- Decorator.cs
- Hyperlink.cs
- ShaderRenderModeValidation.cs
- SerialStream.cs
- TextEndOfLine.cs
- TypeConverterMarkupExtension.cs
- ImageCreator.cs
- DataGridAddNewRow.cs
- LowerCaseStringConverter.cs
- PrePostDescendentsWalker.cs