MergeEnumerator.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / Merging / MergeEnumerator.cs / 1305376 / MergeEnumerator.cs
                        
                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
// =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
// 
// MergeEnumerator.cs 
//
// [....] 
//
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

using System.Collections; 
using System.Collections.Generic;
using System.Diagnostics.Contracts; 
 
namespace System.Linq.Parallel
{ 
    /// 
    /// Convenience class used by enumerators that merge many partitions into one.
    /// 
    ///  
    internal abstract class MergeEnumerator : IEnumerator
    { 
        protected QueryTaskGroupState m_taskGroupState; 

        //------------------------------------------------------------------------------------ 
        // Initializes a new enumerator with the specified group state.
        //

        protected MergeEnumerator(QueryTaskGroupState taskGroupState) 
        {
            Contract.Assert(taskGroupState != null); 
            m_taskGroupState = taskGroupState; 
        }
 
        //-----------------------------------------------------------------------------------
        // Abstract members of IEnumerator that must be implemented by concrete subclasses.
        //
 
        public abstract TInputOutput Current { get; }
 
        public abstract bool MoveNext(); 

        //----------------------------------------------------------------------------------- 
        // Straightforward IEnumerator methods. So subclasses needn't bother.
        //

        object IEnumerator.Current 
        {
            get { return ((IEnumerator)this).Current; } 
        } 

        public virtual void Reset() 
        {
            // (intentionally left blank)
        }
 
        //-----------------------------------------------------------------------------------
        // If the enumerator is disposed of before the query finishes, we need to ensure 
        // we properly tear down the query such that exceptions are not lost. 
        //
 
        public virtual void Dispose()
        {
            // If the enumerator is being disposed of before the query has finished,
            // we will wait for the query to finish.  Cancellation should have already 
            // been initiated, so we just need to ensure exceptions are propagated.
            if (!m_taskGroupState.IsAlreadyEnded) 
            { 
                Contract.Assert(m_taskGroupState.CancellationState.TopLevelDisposedFlag.Value);
                m_taskGroupState.QueryEnd(true); 
            }
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
// =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
// 
// MergeEnumerator.cs 
//
// [....] 
//
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

using System.Collections; 
using System.Collections.Generic;
using System.Diagnostics.Contracts; 
 
namespace System.Linq.Parallel
{ 
    /// 
    /// Convenience class used by enumerators that merge many partitions into one.
    /// 
    ///  
    internal abstract class MergeEnumerator : IEnumerator
    { 
        protected QueryTaskGroupState m_taskGroupState; 

        //------------------------------------------------------------------------------------ 
        // Initializes a new enumerator with the specified group state.
        //

        protected MergeEnumerator(QueryTaskGroupState taskGroupState) 
        {
            Contract.Assert(taskGroupState != null); 
            m_taskGroupState = taskGroupState; 
        }
 
        //-----------------------------------------------------------------------------------
        // Abstract members of IEnumerator that must be implemented by concrete subclasses.
        //
 
        public abstract TInputOutput Current { get; }
 
        public abstract bool MoveNext(); 

        //----------------------------------------------------------------------------------- 
        // Straightforward IEnumerator methods. So subclasses needn't bother.
        //

        object IEnumerator.Current 
        {
            get { return ((IEnumerator)this).Current; } 
        } 

        public virtual void Reset() 
        {
            // (intentionally left blank)
        }
 
        //-----------------------------------------------------------------------------------
        // If the enumerator is disposed of before the query finishes, we need to ensure 
        // we properly tear down the query such that exceptions are not lost. 
        //
 
        public virtual void Dispose()
        {
            // If the enumerator is being disposed of before the query has finished,
            // we will wait for the query to finish.  Cancellation should have already 
            // been initiated, so we just need to ensure exceptions are propagated.
            if (!m_taskGroupState.IsAlreadyEnded) 
            { 
                Contract.Assert(m_taskGroupState.CancellationState.TopLevelDisposedFlag.Value);
                m_taskGroupState.QueryEnd(true); 
            }
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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MergeEnumerator.cs source code in C# .NET

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