Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / wpf / src / Shared / MS / Win32 / handlecollector.cs / 1 / handlecollector.cs
using System; using MS.Win32 ; using System.Runtime.InteropServices; namespace MS.Win32 { internal static class HandleCollector { private static HandleType[] handleTypes; private static int handleTypeCount = 0; private static Object handleMutex = new Object(); ////// Adds the given handle to the handle collector. This keeps the /// handle on a "hot list" of objects that may need to be garbage /// collected. /// internal static IntPtr Add(IntPtr handle, int type) { handleTypes[type - 1].Add(); return handle; } internal static SafeHandle Add(SafeHandle handle, int type) { handleTypes[type - 1].Add(); return handle; } ////// Registers a new type of handle with the handle collector. /// internal static int RegisterType(string typeName, int expense, int initialThreshold) { lock (handleMutex) { if (handleTypeCount == 0 || handleTypeCount == handleTypes.Length) { HandleType[] newTypes = new HandleType[handleTypeCount + 10]; if (handleTypes != null) { Array.Copy(handleTypes, 0, newTypes, 0, handleTypeCount); } handleTypes = newTypes; } handleTypes[handleTypeCount++] = new HandleType(typeName, expense, initialThreshold); return handleTypeCount; } } ////// Removes the given handle from the handle collector. Removing a /// handle removes it from our "hot list" of objects that should be /// frequently garbage collected. /// internal static IntPtr Remove(IntPtr handle, int type) { handleTypes[type - 1].Remove(); return handle ; } internal static SafeHandle Remove(SafeHandle handle, int type) { handleTypes[type - 1].Remove(); return handle ; } ////// Represents a specific type of handle. /// private class HandleType { internal readonly string name; private int initialThreshHold; private int threshHold; private int handleCount; private readonly int deltaPercent; ////// Creates a new handle type. /// internal HandleType(string name, int expense, int initialThreshHold) { this.name = name; this.initialThreshHold = initialThreshHold; this.threshHold = initialThreshHold; this.deltaPercent = 100 - expense; } ////// Adds a handle to this handle type for monitoring. /// internal void Add() { bool performCollect = false; lock(this) { handleCount++; performCollect = NeedCollection(); if (!performCollect) { return; } } if (performCollect) { #if DEBUG_HANDLECOLLECTOR Debug.WriteLine("HC> Forcing garbage collect"); Debug.WriteLine("HC> name :" + name); Debug.WriteLine("HC> threshHold :" + (threshHold).ToString()); Debug.WriteLine("HC> handleCount :" + (handleCount).ToString()); Debug.WriteLine("HC> deltaPercent:" + (deltaPercent).ToString()); #endif GC.Collect(); // We just performed a GC. If the main thread is in a tight // loop there is a this will cause us to increase handles forever and prevent handle collector // from doing its job. Yield the thread here. This won't totally cause // a finalization pass but it will effectively elevate the priority // of the finalizer thread just for an instant. But how long should // we sleep? We base it on how expensive the handles are because the // more expensive the handle, the more critical that it be reclaimed. int sleep = (100 - deltaPercent) / 4; System.Threading.Thread.Sleep(sleep); } } ////// Determines if this handle type needs a garbage collection pass. /// internal bool NeedCollection() { if (handleCount > threshHold) { threshHold = handleCount + ((handleCount * deltaPercent) / 100); #if DEBUG_HANDLECOLLECTOR Debug.WriteLine("HC> NeedCollection: increase threshHold to " + threshHold); #endif return true; } // If handle count < threshHold, we don't // need to collect, but if it 10% below the next lowest threshhold we // will bump down a rung. We need to choose a percentage here or else // we will oscillate. // int oldThreshHold = (100 * threshHold) / (100 + deltaPercent); if (oldThreshHold >= initialThreshHold && handleCount < (int)(oldThreshHold * .9F)) { #if DEBUG_HANDLECOLLECTOR Debug.WriteLine("HC> NeedCollection: throttle threshhold " + threshHold + " down to " + oldThreshHold); #endif threshHold = oldThreshHold; } return false; } ////// Removes the given handle from our monitor list. /// internal void Remove() { lock(this) { handleCount--; handleCount = Math.Max(0, handleCount); } } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. using System; using MS.Win32 ; using System.Runtime.InteropServices; namespace MS.Win32 { internal static class HandleCollector { private static HandleType[] handleTypes; private static int handleTypeCount = 0; private static Object handleMutex = new Object(); ////// Adds the given handle to the handle collector. This keeps the /// handle on a "hot list" of objects that may need to be garbage /// collected. /// internal static IntPtr Add(IntPtr handle, int type) { handleTypes[type - 1].Add(); return handle; } internal static SafeHandle Add(SafeHandle handle, int type) { handleTypes[type - 1].Add(); return handle; } ////// Registers a new type of handle with the handle collector. /// internal static int RegisterType(string typeName, int expense, int initialThreshold) { lock (handleMutex) { if (handleTypeCount == 0 || handleTypeCount == handleTypes.Length) { HandleType[] newTypes = new HandleType[handleTypeCount + 10]; if (handleTypes != null) { Array.Copy(handleTypes, 0, newTypes, 0, handleTypeCount); } handleTypes = newTypes; } handleTypes[handleTypeCount++] = new HandleType(typeName, expense, initialThreshold); return handleTypeCount; } } ////// Removes the given handle from the handle collector. Removing a /// handle removes it from our "hot list" of objects that should be /// frequently garbage collected. /// internal static IntPtr Remove(IntPtr handle, int type) { handleTypes[type - 1].Remove(); return handle ; } internal static SafeHandle Remove(SafeHandle handle, int type) { handleTypes[type - 1].Remove(); return handle ; } ////// Represents a specific type of handle. /// private class HandleType { internal readonly string name; private int initialThreshHold; private int threshHold; private int handleCount; private readonly int deltaPercent; ////// Creates a new handle type. /// internal HandleType(string name, int expense, int initialThreshHold) { this.name = name; this.initialThreshHold = initialThreshHold; this.threshHold = initialThreshHold; this.deltaPercent = 100 - expense; } ////// Adds a handle to this handle type for monitoring. /// internal void Add() { bool performCollect = false; lock(this) { handleCount++; performCollect = NeedCollection(); if (!performCollect) { return; } } if (performCollect) { #if DEBUG_HANDLECOLLECTOR Debug.WriteLine("HC> Forcing garbage collect"); Debug.WriteLine("HC> name :" + name); Debug.WriteLine("HC> threshHold :" + (threshHold).ToString()); Debug.WriteLine("HC> handleCount :" + (handleCount).ToString()); Debug.WriteLine("HC> deltaPercent:" + (deltaPercent).ToString()); #endif GC.Collect(); // We just performed a GC. If the main thread is in a tight // loop there is a this will cause us to increase handles forever and prevent handle collector // from doing its job. Yield the thread here. This won't totally cause // a finalization pass but it will effectively elevate the priority // of the finalizer thread just for an instant. But how long should // we sleep? We base it on how expensive the handles are because the // more expensive the handle, the more critical that it be reclaimed. int sleep = (100 - deltaPercent) / 4; System.Threading.Thread.Sleep(sleep); } } ////// Determines if this handle type needs a garbage collection pass. /// internal bool NeedCollection() { if (handleCount > threshHold) { threshHold = handleCount + ((handleCount * deltaPercent) / 100); #if DEBUG_HANDLECOLLECTOR Debug.WriteLine("HC> NeedCollection: increase threshHold to " + threshHold); #endif return true; } // If handle count < threshHold, we don't // need to collect, but if it 10% below the next lowest threshhold we // will bump down a rung. We need to choose a percentage here or else // we will oscillate. // int oldThreshHold = (100 * threshHold) / (100 + deltaPercent); if (oldThreshHold >= initialThreshHold && handleCount < (int)(oldThreshHold * .9F)) { #if DEBUG_HANDLECOLLECTOR Debug.WriteLine("HC> NeedCollection: throttle threshhold " + threshHold + " down to " + oldThreshHold); #endif threshHold = oldThreshHold; } return false; } ////// Removes the given handle from our monitor list. /// internal void Remove() { lock(this) { handleCount--; handleCount = Math.Max(0, handleCount); } } } } } // 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
- NameObjectCollectionBase.cs
- DataReaderContainer.cs
- NamedPipeConnectionPoolSettings.cs
- RectangleHotSpot.cs
- WebServiceResponseDesigner.cs
- DataGridCell.cs
- ServiceDocument.cs
- DecimalFormatter.cs
- Scene3D.cs
- CodeCompiler.cs
- ContentPosition.cs
- CacheChildrenQuery.cs
- QilGeneratorEnv.cs
- DesignTimeParseData.cs
- TextPattern.cs
- Encoder.cs
- TriggerBase.cs
- LogicalMethodInfo.cs
- UrlMappingsSection.cs
- SiteMapSection.cs
- FaultContractAttribute.cs
- EntryWrittenEventArgs.cs
- TimeoutException.cs
- DataGridViewRowContextMenuStripNeededEventArgs.cs
- OperationBehaviorAttribute.cs
- Privilege.cs
- COM2DataTypeToManagedDataTypeConverter.cs
- AttributeUsageAttribute.cs
- ApplicationGesture.cs
- ListenerConfig.cs
- PropertyChangedEventManager.cs
- UpDownBaseDesigner.cs
- SQLDateTime.cs
- ContextMenuAutomationPeer.cs
- GZipDecoder.cs
- PolyQuadraticBezierSegment.cs
- DocumentViewerAutomationPeer.cs
- BitmapEffectDrawingContent.cs
- CellIdBoolean.cs
- LazyTextWriterCreator.cs
- WebPartAddingEventArgs.cs
- PersonalizationProviderCollection.cs
- LinkedDataMemberFieldEditor.cs
- FixedTextPointer.cs
- XmlBoundElement.cs
- ISAPIRuntime.cs
- SafeProcessHandle.cs
- SplitterEvent.cs
- HealthMonitoringSection.cs
- SplayTreeNode.cs
- PagedDataSource.cs
- TokenDescriptor.cs
- FixedLineResult.cs
- OdbcDataAdapter.cs
- TypeUnloadedException.cs
- CopyCodeAction.cs
- LinqDataSourceStatusEventArgs.cs
- ScriptModule.cs
- DataGridViewSelectedCellCollection.cs
- AuthorizationRule.cs
- Storyboard.cs
- ManualResetEvent.cs
- base64Transforms.cs
- Converter.cs
- TableCellsCollectionEditor.cs
- WebServiceReceiveDesigner.cs
- EntityClientCacheEntry.cs
- PartialTrustHelpers.cs
- MatrixTransform.cs
- ZoneMembershipCondition.cs
- InputLanguageProfileNotifySink.cs
- x509utils.cs
- MsmqIntegrationChannelFactory.cs
- PixelShader.cs
- SafeNativeMemoryHandle.cs
- IssuedTokenClientCredential.cs
- Pen.cs
- ListViewInsertedEventArgs.cs
- DateTimeValueSerializerContext.cs
- AssociationSetMetadata.cs
- BamlVersionHeader.cs
- ISAPIRuntime.cs
- ZipPackagePart.cs
- MenuAutomationPeer.cs
- SqlClientWrapperSmiStreamChars.cs
- FormViewDeleteEventArgs.cs
- SetStateEventArgs.cs
- ChooseAction.cs
- Bezier.cs
- SelectorItemAutomationPeer.cs
- DataSvcMapFileSerializer.cs
- DataComponentGenerator.cs
- StringFunctions.cs
- CommandDesigner.cs
- DesignerEditorPartChrome.cs
- ThicknessAnimation.cs
- HtmlString.cs
- FormView.cs
- XslNumber.cs
- XmlTypeAttribute.cs