Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / Enumerables / RangeEnumerable.cs / 1305376 / RangeEnumerable.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // RangeEnumerable.cs // //[....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Collections.Generic; namespace System.Linq.Parallel { ////// A simple enumerable type that implements the range algorithm. It also supports /// partitioning of the indices by implementing an interface that PLINQ recognizes. /// internal class RangeEnumerable : ParallelQuery, IParallelPartitionable { private int m_from; // Lowest index to include. private int m_count; // Number of indices to include. //------------------------------------------------------------------------------------ // Constructs a new range enumerable object for the specified range. // internal RangeEnumerable(int from, int count) :base(QuerySettings.Empty) { // Transform the from and to indices into low and highs. m_from = from; m_count = count; } //----------------------------------------------------------------------------------- // Retrieves 'count' partitions, each of which uses a non-overlapping set of indices. // public QueryOperatorEnumerator [] GetPartitions(int partitionCount) { // Calculate a stride size, avoiding overflow if m_count is large int stride = m_count / partitionCount; int biggerPartitionCount = m_count % partitionCount; // Create individual partitions, carefully avoiding overflow int doneCount = 0; QueryOperatorEnumerator [] partitions = new QueryOperatorEnumerator [partitionCount]; for (int i = 0; i < partitionCount; i++) { int partitionSize = (i < biggerPartitionCount) ? stride + 1 : stride; partitions[i] = new RangeEnumerator( m_from + doneCount, partitionSize, doneCount); doneCount += partitionSize; } return partitions; } //----------------------------------------------------------------------------------- // Basic IEnumerator method implementations. // public override IEnumerator GetEnumerator() { return new RangeEnumerator(m_from, m_count, 0).AsClassicEnumerator(); } //----------------------------------------------------------------------------------- // The actual enumerator that walks over the specified range. // class RangeEnumerator : QueryOperatorEnumerator { private readonly int m_from; // The initial value. private readonly int m_count; // How many values to yield. private readonly int m_initialIndex; // The ordinal index of the first value in the range. private Shared m_currentCount; // The 0-based index of the current value. [allocate in moveNext to avoid false-sharing] //------------------------------------------------------------------------------------ // Creates a new enumerator. // internal RangeEnumerator(int from, int count, int initialIndex) { m_from = from; m_count = count; m_initialIndex = initialIndex; } //----------------------------------------------------------------------------------- // Basic enumeration method. This implements the logic to walk the desired // range, using the step specified at construction time. // internal override bool MoveNext(ref int currentElement, ref int currentKey) { if( m_currentCount == null) m_currentCount = new Shared (-1); // Calculate the next index and ensure it falls within our range. int nextCount = m_currentCount.Value + 1; if (nextCount < m_count) { m_currentCount.Value = nextCount; currentElement = nextCount + m_from; currentKey = nextCount + m_initialIndex; return true; } return false; } internal override void Reset() { // We set the current value such that the next addition of step // results in the 1st real value in the range. m_currentCount = null; } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // RangeEnumerable.cs // // [....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Collections.Generic; namespace System.Linq.Parallel { ////// A simple enumerable type that implements the range algorithm. It also supports /// partitioning of the indices by implementing an interface that PLINQ recognizes. /// internal class RangeEnumerable : ParallelQuery, IParallelPartitionable { private int m_from; // Lowest index to include. private int m_count; // Number of indices to include. //------------------------------------------------------------------------------------ // Constructs a new range enumerable object for the specified range. // internal RangeEnumerable(int from, int count) :base(QuerySettings.Empty) { // Transform the from and to indices into low and highs. m_from = from; m_count = count; } //----------------------------------------------------------------------------------- // Retrieves 'count' partitions, each of which uses a non-overlapping set of indices. // public QueryOperatorEnumerator [] GetPartitions(int partitionCount) { // Calculate a stride size, avoiding overflow if m_count is large int stride = m_count / partitionCount; int biggerPartitionCount = m_count % partitionCount; // Create individual partitions, carefully avoiding overflow int doneCount = 0; QueryOperatorEnumerator [] partitions = new QueryOperatorEnumerator [partitionCount]; for (int i = 0; i < partitionCount; i++) { int partitionSize = (i < biggerPartitionCount) ? stride + 1 : stride; partitions[i] = new RangeEnumerator( m_from + doneCount, partitionSize, doneCount); doneCount += partitionSize; } return partitions; } //----------------------------------------------------------------------------------- // Basic IEnumerator method implementations. // public override IEnumerator GetEnumerator() { return new RangeEnumerator(m_from, m_count, 0).AsClassicEnumerator(); } //----------------------------------------------------------------------------------- // The actual enumerator that walks over the specified range. // class RangeEnumerator : QueryOperatorEnumerator { private readonly int m_from; // The initial value. private readonly int m_count; // How many values to yield. private readonly int m_initialIndex; // The ordinal index of the first value in the range. private Shared m_currentCount; // The 0-based index of the current value. [allocate in moveNext to avoid false-sharing] //------------------------------------------------------------------------------------ // Creates a new enumerator. // internal RangeEnumerator(int from, int count, int initialIndex) { m_from = from; m_count = count; m_initialIndex = initialIndex; } //----------------------------------------------------------------------------------- // Basic enumeration method. This implements the logic to walk the desired // range, using the step specified at construction time. // internal override bool MoveNext(ref int currentElement, ref int currentKey) { if( m_currentCount == null) m_currentCount = new Shared (-1); // Calculate the next index and ensure it falls within our range. int nextCount = m_currentCount.Value + 1; if (nextCount < m_count) { m_currentCount.Value = nextCount; currentElement = nextCount + m_from; currentKey = nextCount + m_initialIndex; return true; } return false; } internal override void Reset() { // We set the current value such that the next addition of step // results in the 1st real value in the range. m_currentCount = null; } } } } // 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
- CachedTypeface.cs
- Subset.cs
- TemplateControlCodeDomTreeGenerator.cs
- PixelFormatConverter.cs
- ByteStack.cs
- DocComment.cs
- SmiEventSink_Default.cs
- OrderedDictionary.cs
- BlurBitmapEffect.cs
- StylusDownEventArgs.cs
- LabelTarget.cs
- SerialErrors.cs
- SortFieldComparer.cs
- SatelliteContractVersionAttribute.cs
- SessionEndedEventArgs.cs
- ReliableSessionBindingElementImporter.cs
- ProcessThreadCollection.cs
- SapiAttributeParser.cs
- HandledEventArgs.cs
- DiagnosticTrace.cs
- URLAttribute.cs
- HtmlTextBoxAdapter.cs
- ProfilePropertyNameValidator.cs
- HtmlTitle.cs
- WorkflowViewStateService.cs
- ProgressBarHighlightConverter.cs
- LogSwitch.cs
- Error.cs
- MemoryMappedFile.cs
- MetadataArtifactLoaderCompositeFile.cs
- ToolStripPanelCell.cs
- InputManager.cs
- GraphicsPath.cs
- DataRow.cs
- WindowsContainer.cs
- DbSetClause.cs
- ExtensionSimplifierMarkupObject.cs
- WinCategoryAttribute.cs
- AQNBuilder.cs
- OdbcError.cs
- X509UI.cs
- Convert.cs
- MouseActionConverter.cs
- SmtpSpecifiedPickupDirectoryElement.cs
- Literal.cs
- TempEnvironment.cs
- ViewValidator.cs
- InputReferenceExpression.cs
- FixedHighlight.cs
- Mapping.cs
- _FtpControlStream.cs
- RootBrowserWindow.cs
- XpsResourceDictionary.cs
- EndpointReference.cs
- OuterGlowBitmapEffect.cs
- NoResizeSelectionBorderGlyph.cs
- MetadataCacheItem.cs
- TemplateControlParser.cs
- WhitespaceRuleReader.cs
- XmlArrayItemAttributes.cs
- _AcceptOverlappedAsyncResult.cs
- SqlDataSourceStatusEventArgs.cs
- Context.cs
- XPathCompiler.cs
- ProgressBarRenderer.cs
- PngBitmapEncoder.cs
- ScriptingProfileServiceSection.cs
- RelationHandler.cs
- WindowPattern.cs
- WebPartMenu.cs
- EnumerableRowCollection.cs
- BaseTemplateParser.cs
- SaveFileDialog.cs
- MenuItemStyle.cs
- StorageAssociationTypeMapping.cs
- HttpRuntimeSection.cs
- DetailsViewUpdatedEventArgs.cs
- Bitmap.cs
- HostedHttpRequestAsyncResult.cs
- PositiveTimeSpanValidator.cs
- BinaryParser.cs
- IsolatedStorageFileStream.cs
- ConfigurationManagerInternalFactory.cs
- Icon.cs
- ProbeMatchesMessage11.cs
- EUCJPEncoding.cs
- SourceSwitch.cs
- ClipboardProcessor.cs
- HttpWrapper.cs
- ClientFormsIdentity.cs
- Vector3D.cs
- CellIdBoolean.cs
- SplineQuaternionKeyFrame.cs
- RegexEditorDialog.cs
- CssTextWriter.cs
- Baml2006ReaderSettings.cs
- AnnotationService.cs
- Clause.cs
- AdvancedBindingPropertyDescriptor.cs
- DependencyPropertyValueSerializer.cs