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/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / QueryOperators / QuerySettings.cs / 1305376 / QuerySettings.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // QuerySettings.cs // //[....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Threading; using System.Threading.Tasks; using System.Diagnostics.Contracts; namespace System.Linq.Parallel { ////// This type contains query execution options specified by the user. /// QuerySettings are used as follows: /// - in the query construction phase, some settings may be uninitialized. /// - at the start of the query opening phase, the WithDefaults method /// is used to initialize all uninitialized settings. /// - in the rest of the query opening phase, we assume that all settings /// have been initialized. /// internal struct QuerySettings { private TaskScheduler m_taskScheduler; private int? m_degreeOfParallelism; private CancellationState m_cancellationState; private ParallelExecutionMode? m_executionMode; private ParallelMergeOptions? m_mergeOptions; private int m_queryId; internal CancellationState CancellationState { get { return m_cancellationState; } set { m_cancellationState = value; Contract.Assert(m_cancellationState != null); } } // The task manager on which to execute the query. internal TaskScheduler TaskScheduler { get { return m_taskScheduler; } set { m_taskScheduler = value; } } // The number of parallel tasks to utilize. internal int? DegreeOfParallelism { get { return m_degreeOfParallelism; } set { m_degreeOfParallelism = value; } } // The mode in which to execute this query. internal ParallelExecutionMode? ExecutionMode { get { return m_executionMode; } set { m_executionMode = value; } } internal ParallelMergeOptions? MergeOptions { get { return m_mergeOptions; } set { m_mergeOptions = value; } } internal int QueryId { get { return m_queryId; } } //------------------------------------------------------------------------------------ // Constructs a new settings structure. // internal QuerySettings(TaskScheduler taskScheduler, int? degreeOfParallelism, CancellationToken externalCancellationToken, ParallelExecutionMode? executionMode, ParallelMergeOptions? mergeOptions) { m_taskScheduler = taskScheduler; m_degreeOfParallelism = degreeOfParallelism; m_cancellationState = new CancellationState(externalCancellationToken); m_executionMode = executionMode; m_mergeOptions = mergeOptions; m_queryId = -1; Contract.Assert(m_cancellationState != null); } //----------------------------------------------------------------------------------- // Combines two sets of options. // internal QuerySettings Merge(QuerySettings settings2) { if (this.TaskScheduler != null && settings2.TaskScheduler != null) { throw new InvalidOperationException(SR.GetString(SR.ParallelQuery_DuplicateTaskScheduler)); } if (this.DegreeOfParallelism != null && settings2.DegreeOfParallelism != null) { throw new InvalidOperationException(SR.GetString(SR.ParallelQuery_DuplicateDOP)); } if (this.CancellationState.ExternalCancellationToken.CanBeCanceled && settings2.CancellationState.ExternalCancellationToken.CanBeCanceled) { throw new InvalidOperationException(SR.GetString(SR.ParallelQuery_DuplicateWithCancellation)); } if (this.ExecutionMode != null && settings2.ExecutionMode != null) { throw new InvalidOperationException(SR.GetString(SR.ParallelQuery_DuplicateExecutionMode)); } if (this.MergeOptions != null && settings2.MergeOptions != null) { throw new InvalidOperationException(SR.GetString(SR.ParallelQuery_DuplicateMergeOptions)); } TaskScheduler tm = (this.TaskScheduler == null) ? settings2.TaskScheduler : this.TaskScheduler; int? dop = this.DegreeOfParallelism.HasValue ? this.DegreeOfParallelism : settings2.DegreeOfParallelism; CancellationToken externalCancellationToken = (this.CancellationState.ExternalCancellationToken.CanBeCanceled) ? this.CancellationState.ExternalCancellationToken : settings2.CancellationState.ExternalCancellationToken; ParallelExecutionMode? executionMode = this.ExecutionMode.HasValue ? this.ExecutionMode : settings2.ExecutionMode; ParallelMergeOptions? mergeOptions = this.MergeOptions.HasValue ? this.MergeOptions : settings2.MergeOptions; return new QuerySettings(tm, dop, externalCancellationToken, executionMode, mergeOptions); } internal QuerySettings WithPerExecutionSettings() { return WithPerExecutionSettings(new CancellationTokenSource(), new Shared(false)); } internal QuerySettings WithPerExecutionSettings(CancellationTokenSource topLevelCancellationTokenSource, Shared topLevelDisposedFlag) { //Initialize a new QuerySettings structure and copy in the current settings. //Note: this has the very important effect of newing a fresh CancellationSettings, // and _not_ copying in the current internalCancellationSource or topLevelDisposedFlag which should not be // propogated to internal query executions. (This affects SelectMany execution and specifically fixes bug:535510) // The fresh toplevel parameters are used instead. QuerySettings settings = new QuerySettings(TaskScheduler, DegreeOfParallelism, CancellationState.ExternalCancellationToken, ExecutionMode, MergeOptions); Contract.Assert(topLevelCancellationTokenSource != null, "There should always be a top-level cancellation signal specified."); settings.CancellationState.InternalCancellationTokenSource = topLevelCancellationTokenSource; //Merge internal and external tokens to form the combined token settings.CancellationState.MergedCancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(settings.CancellationState.InternalCancellationTokenSource.Token, settings.CancellationState.ExternalCancellationToken); // and copy in the topLevelDisposedFlag settings.CancellationState.TopLevelDisposedFlag = topLevelDisposedFlag; Contract.Assert(settings.CancellationState.InternalCancellationTokenSource != null); Contract.Assert(settings.CancellationState.MergedCancellationToken.CanBeCanceled); Contract.Assert(settings.CancellationState.TopLevelDisposedFlag != null); // Finally, assign a query Id to the settings #if !PFX_LEGACY_3_5 settings.m_queryId = PlinqEtwProvider.NextQueryId(); #endif return settings; } //----------------------------------------------------------------------------------- // Copies the settings, replacing unspecified settings with defaults. // internal QuerySettings WithDefaults() { QuerySettings settings = this; if (settings.TaskScheduler == null) { settings.TaskScheduler = TaskScheduler.Default; } if (settings.DegreeOfParallelism == null) { settings.DegreeOfParallelism = Scheduling.GetDefaultDegreeOfParallelism(); } if (settings.ExecutionMode == null) { settings.ExecutionMode = ParallelExecutionMode.Default; } if (settings.MergeOptions == null) { settings.MergeOptions = ParallelMergeOptions.Default; } if (settings.MergeOptions == ParallelMergeOptions.Default) { settings.MergeOptions = ParallelMergeOptions.AutoBuffered; } Contract.Assert(settings.TaskScheduler != null); Contract.Assert(settings.DegreeOfParallelism.HasValue); Contract.Assert(settings.DegreeOfParallelism.Value >= 1 && settings.DegreeOfParallelism <= Scheduling.MAX_SUPPORTED_DOP); Contract.Assert(settings.ExecutionMode != null); Contract.Assert(settings.MergeOptions != null); Contract.Assert(settings.MergeOptions != ParallelMergeOptions.Default); return settings; } // Returns the default settings internal static QuerySettings Empty { get { return new QuerySettings(null, null, new CancellationToken(), null, null); } } // Cleanup internal state once the entire query is complete. // (this should not be performed after a 'premature-query' completes as the state should live // uninterrupted for the duration of the full query.) public void CleanStateAtQueryEnd() { m_cancellationState.MergedCancellationTokenSource.Dispose(); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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