1 files changed, 1035 insertions, 0 deletions

diff --git a/ThirdParty/SmartThreadPool/WorkItem.cs b/ThirdParty/SmartThreadPool/WorkItem.cs
new file mode 100644
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+++ b/ThirdParty/SmartThreadPool/WorkItem.cs
@@ -0,0 +1,1035 @@
+// Ami Bar
+// amibar@gmail.com
+
+using System;
+using System.Threading;
+using System.Diagnostics;
+
+namespace Amib.Threading.Internal
+{
+    #region WorkItem Delegate
+
+    /// <summary>
+    /// An internal delegate to call when the WorkItem starts or completes
+    /// </summary>
+    internal delegate void WorkItemStateCallback(WorkItem workItem);
+
+    #endregion
+
+    #region IInternalWorkItemResult interface 
+
+    public class CanceledWorkItemsGroup
+    {
+        public readonly static CanceledWorkItemsGroup NotCanceledWorkItemsGroup = new CanceledWorkItemsGroup();
+
+        private bool _isCanceled = false;
+        public bool IsCanceled 
+        { 
+            get { return _isCanceled; }
+            set { _isCanceled = value; }
+        }
+    }
+
+    internal interface IInternalWorkItemResult
+    {
+        event WorkItemStateCallback OnWorkItemStarted;
+        event WorkItemStateCallback OnWorkItemCompleted;
+    }
+
+    #endregion
+
+    #region IWorkItem interface
+
+    public interface IWorkItem
+    {
+
+    }
+
+    #endregion
+
+    #region WorkItem class
+
+    /// <summary>
+    /// Holds a callback delegate and the state for that delegate.
+    /// </summary>
+    public class WorkItem : IHasWorkItemPriority, IWorkItem
+    {
+        #region WorkItemState enum
+
+        /// <summary>
+        /// Indicates the state of the work item in the thread pool
+        /// </summary>
+        private enum WorkItemState
+        {
+            InQueue,
+            InProgress,
+            Completed,
+            Canceled,
+        }
+
+        #endregion
+
+        #region Member Variables
+
+        public Thread currentThread;
+
+        /// <summary>
+        /// Callback delegate for the callback.
+        /// </summary>
+        private WorkItemCallback _callback;
+
+        /// <summary>
+        /// State with which to call the callback delegate.
+        /// </summary>
+        private object _state;
+
+        /// <summary>
+        /// Stores the caller's context
+        /// </summary>
+        private CallerThreadContext _callerContext;
+
+        /// <summary>
+        /// Holds the result of the mehtod
+        /// </summary>
+        private object _result;
+
+        /// <summary>
+        /// Hold the exception if the method threw it
+        /// </summary>
+        private Exception _exception;
+
+        /// <summary>
+        /// Hold the state of the work item
+        /// </summary>
+        private WorkItemState _workItemState;
+
+        /// <summary>
+        /// A ManualResetEvent to indicate that the result is ready
+        /// </summary>
+        private ManualResetEvent _workItemCompleted;
+
+        /// <summary>
+        /// A reference count to the _workItemCompleted. 
+        /// When it reaches to zero _workItemCompleted is Closed
+        /// </summary>
+        private int _workItemCompletedRefCount;
+
+        /// <summary>
+        /// Represents the result state of the work item
+        /// </summary>
+        private WorkItemResult _workItemResult;
+
+        /// <summary>
+        /// Work item info
+        /// </summary>
+        private WorkItemInfo _workItemInfo;
+
+        /// <summary>
+        /// Called when the WorkItem starts
+        /// </summary>
+        private event WorkItemStateCallback _workItemStartedEvent;
+
+        /// <summary>
+        /// Called when the WorkItem completes
+        /// </summary>
+        private event WorkItemStateCallback _workItemCompletedEvent;
+
+        /// <summary>
+        /// A reference to an object that indicates whatever the 
+        /// WorkItemsGroup has been canceled
+        /// </summary>
+        private CanceledWorkItemsGroup _canceledWorkItemsGroup = CanceledWorkItemsGroup.NotCanceledWorkItemsGroup;
+
+        /// <summary>
+        /// The work item group this work item belong to.
+        /// 
+        /// </summary>
+        private IWorkItemsGroup _workItemsGroup;
+
+        #region Performance Counter fields
+
+        /// <summary>
+        /// The time when the work items is queued.
+        /// Used with the performance counter.
+        /// </summary>
+        private DateTime _queuedTime;
+
+        /// <summary>
+        /// The time when the work items starts its execution.
+        /// Used with the performance counter.
+        /// </summary>
+        private DateTime _beginProcessTime;
+
+        /// <summary>
+        /// The time when the work items ends its execution.
+        /// Used with the performance counter.
+        /// </summary>
+        private DateTime _endProcessTime;
+
+        #endregion
+
+        #endregion
+
+        #region Properties
+
+        public TimeSpan WaitingTime
+        {
+            get 
+            {
+                return (_beginProcessTime - _queuedTime);
+            }
+        }
+
+        public TimeSpan ProcessTime
+        {
+            get 
+            {
+                return (_endProcessTime - _beginProcessTime);
+            }
+        }
+
+        #endregion
+
+        #region Construction
+
+        /// <summary>
+        /// Initialize the callback holding object.
+        /// </summary>
+        /// <param name="callback">Callback delegate for the callback.</param>
+        /// <param name="state">State with which to call the callback delegate.</param>
+        /// 
+        /// We assume that the WorkItem object is created within the thread
+        /// that meant to run the callback
+        public WorkItem(
+            IWorkItemsGroup workItemsGroup,
+            WorkItemInfo workItemInfo,
+            WorkItemCallback callback, 
+            object state)
+        {
+            _workItemsGroup = workItemsGroup;
+            _workItemInfo = workItemInfo;
+
+            if (_workItemInfo.UseCallerCallContext || _workItemInfo.UseCallerHttpContext)
+            {
+                _callerContext = CallerThreadContext.Capture(_workItemInfo.UseCallerCallContext, _workItemInfo.UseCallerHttpContext);
+            }
+
+            _callback = callback;
+            _state = state;
+            _workItemResult = new WorkItemResult(this);
+            Initialize();
+        }
+
+        internal void Initialize()
+        {
+            _workItemState = WorkItemState.InQueue;
+            _workItemCompleted = null;
+            _workItemCompletedRefCount = 0;
+        }
+
+        internal bool WasQueuedBy(IWorkItemsGroup workItemsGroup)
+        {
+            return (workItemsGroup == _workItemsGroup);
+        }
+
+
+        #endregion
+
+        #region Methods
+
+        public CanceledWorkItemsGroup CanceledWorkItemsGroup
+        {
+            get
+            {
+                return _canceledWorkItemsGroup;
+            }
+
+            set
+            {
+                _canceledWorkItemsGroup = value;
+            }
+        }
+
+        /// <summary>
+        /// Change the state of the work item to in progress if it wasn't canceled.
+        /// </summary>
+        /// <returns>
+        /// Return true on success or false in case the work item was canceled.
+        /// If the work item needs to run a post execute then the method will return true.
+        /// </returns>
+        public bool StartingWorkItem()
+        {
+            _beginProcessTime = DateTime.Now;
+
+            lock(this)
+            {
+                if (IsCanceled)
+                {
+                    bool result = false;
+                    if ((_workItemInfo.PostExecuteWorkItemCallback != null) &&
+                        ((_workItemInfo.CallToPostExecute & CallToPostExecute.WhenWorkItemCanceled) == CallToPostExecute.WhenWorkItemCanceled))
+                    {
+                        result = true;
+                    }
+
+                    return result;
+                }
+
+                Debug.Assert(WorkItemState.InQueue == GetWorkItemState());
+
+                SetWorkItemState(WorkItemState.InProgress);
+            }
+
+            return true;
+        }
+
+        /// <summary>
+        /// Execute the work item and the post execute
+        /// </summary>
+        public void Execute()
+        {
+            CallToPostExecute currentCallToPostExecute = 0;
+
+            // Execute the work item if we are in the correct state
+            switch(GetWorkItemState())
+            {
+                case WorkItemState.InProgress:
+                    currentCallToPostExecute |= CallToPostExecute.WhenWorkItemNotCanceled;
+                    ExecuteWorkItem();
+                    break;
+                case WorkItemState.Canceled:
+                    currentCallToPostExecute |= CallToPostExecute.WhenWorkItemCanceled;
+                    break;
+                default:
+                    Debug.Assert(false);
+                    throw new NotSupportedException();
+            }
+
+            // Run the post execute as needed
+            if ((currentCallToPostExecute & _workItemInfo.CallToPostExecute) != 0)
+            {
+                PostExecute();
+            }
+
+            _endProcessTime = DateTime.Now;
+        }
+
+        internal void FireWorkItemCompleted()
+        {
+            try
+            {
+                if (null != _workItemCompletedEvent)
+                {
+                    _workItemCompletedEvent(this);
+                }
+            }
+            catch // Ignore exceptions
+            {}
+        }
+
+        /// <summary>
+        /// Execute the work item
+        /// </summary>
+        private void ExecuteWorkItem()
+        {
+            CallerThreadContext ctc = null;
+            if (null != _callerContext)
+            {
+                ctc = CallerThreadContext.Capture(_callerContext.CapturedCallContext, _callerContext.CapturedHttpContext);
+                CallerThreadContext.Apply(_callerContext);
+            }
+
+            Exception exception = null;
+            object result = null;
+
+            try
+            {
+                result = _callback(_state);
+            }
+            catch (Exception e) 
+            {
+                // Save the exception so we can rethrow it later
+                exception = e;
+            }
+        
+            if (null != _callerContext)
+            {
+                CallerThreadContext.Apply(ctc);
+            }
+
+            SetResult(result, exception);
+        }
+
+        /// <summary>
+        /// Runs the post execute callback
+        /// </summary>
+        private void PostExecute()
+        {
+            if (null != _workItemInfo.PostExecuteWorkItemCallback)
+            {
+                try
+                {
+                    _workItemInfo.PostExecuteWorkItemCallback(this._workItemResult);
+                }
+                catch (Exception e) 
+                {
+                    Debug.Assert(null != e);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Set the result of the work item to return
+        /// </summary>
+        /// <param name="result">The result of the work item</param>
+        internal void SetResult(object result, Exception exception)
+        {
+            _result = result;
+            _exception = exception;
+            SignalComplete(false);
+        }
+
+        /// <summary>
+        /// Returns the work item result
+        /// </summary>
+        /// <returns>The work item result</returns>
+        internal IWorkItemResult GetWorkItemResult()
+        {
+            return _workItemResult;
+        }
+
+        /// <summary>
+        /// Wait for all work items to complete
+        /// </summary>
+        /// <param name="workItemResults">Array of work item result objects</param>
+        /// <param name="millisecondsTimeout">The number of milliseconds to wait, or Timeout.Infinite (-1) to wait indefinitely.</param>
+        /// <param name="exitContext">
+        /// true to exit the synchronization domain for the context before the wait (if in a synchronized context), and reacquire it; otherwise, false. 
+        /// </param>
+        /// <param name="cancelWaitHandle">A cancel wait handle to interrupt the wait if needed</param>
+        /// <returns>
+        /// true when every work item in workItemResults has completed; otherwise false.
+        /// </returns>
+        internal static bool WaitAll(
+            IWorkItemResult [] workItemResults,
+            int millisecondsTimeout,
+            bool exitContext,
+            WaitHandle cancelWaitHandle)
+        {
+            if (0 == workItemResults.Length)
+            {
+                return true;
+            }
+
+            bool success;
+            WaitHandle [] waitHandles = new WaitHandle[workItemResults.Length];;
+            GetWaitHandles(workItemResults, waitHandles);
+
+            if ((null == cancelWaitHandle) && (waitHandles.Length <= 64))
+            {
+                success = WaitHandle.WaitAll(waitHandles, millisecondsTimeout, exitContext);
+            }
+            else
+            {
+                success = true;
+                int millisecondsLeft = millisecondsTimeout;
+                DateTime start = DateTime.Now;
+
+                WaitHandle [] whs;
+                if (null != cancelWaitHandle)
+                {
+                    whs = new WaitHandle [] { null, cancelWaitHandle };
+                }
+                else
+                {
+                    whs = new WaitHandle [] { null };
+                }
+
+                bool waitInfinitely = (Timeout.Infinite == millisecondsTimeout);
+                // Iterate over the wait handles and wait for each one to complete.
+                // We cannot use WaitHandle.WaitAll directly, because the cancelWaitHandle
+                // won't affect it.
+                // Each iteration we update the time left for the timeout.
+                for(int i = 0; i < workItemResults.Length; ++i)
+                {
+                    // WaitAny don't work with negative numbers
+                    if (!waitInfinitely && (millisecondsLeft < 0))
+                    {
+                        success = false;
+                        break;
+                    }
+
+                    whs[0] = waitHandles[i];
+                    int result = WaitHandle.WaitAny(whs, millisecondsLeft, exitContext);
+                    if((result > 0) || (WaitHandle.WaitTimeout == result))
+                    {
+                        success = false;
+                        break;
+                    }
+
+                    if(!waitInfinitely)
+                    {
+                        // Update the time left to wait
+                        TimeSpan ts = DateTime.Now - start;
+                        millisecondsLeft = millisecondsTimeout - (int)ts.TotalMilliseconds;
+                    }
+                }
+            }
+            // Release the wait handles
+            ReleaseWaitHandles(workItemResults);
+
+            return success;
+        }
+
+        /// <summary>
+        /// Waits for any of the work items in the specified array to complete, cancel, or timeout
+        /// </summary>
+        /// <param name="workItemResults">Array of work item result objects</param>
+        /// <param name="millisecondsTimeout">The number of milliseconds to wait, or Timeout.Infinite (-1) to wait indefinitely.</param>
+        /// <param name="exitContext">
+        /// true to exit the synchronization domain for the context before the wait (if in a synchronized context), and reacquire it; otherwise, false. 
+        /// </param>
+        /// <param name="cancelWaitHandle">A cancel wait handle to interrupt the wait if needed</param>
+        /// <returns>
+        /// The array index of the work item result that satisfied the wait, or WaitTimeout if no work item result satisfied the wait and a time interval equivalent to millisecondsTimeout has passed or the work item has been canceled.
+        /// </returns>
+        internal static int WaitAny(            
+            IWorkItemResult [] workItemResults,
+            int millisecondsTimeout,
+            bool exitContext,
+            WaitHandle cancelWaitHandle)
+        {
+            WaitHandle [] waitHandles = null;
+
+            if (null != cancelWaitHandle)
+            {
+                waitHandles = new WaitHandle[workItemResults.Length+1];
+                GetWaitHandles(workItemResults, waitHandles);
+                waitHandles[workItemResults.Length] = cancelWaitHandle;
+            }
+            else
+            {
+                waitHandles = new WaitHandle[workItemResults.Length];
+                GetWaitHandles(workItemResults, waitHandles);
+            }
+
+            int result = WaitHandle.WaitAny(waitHandles, millisecondsTimeout, exitContext);
+
+            // Treat cancel as timeout
+            if (null != cancelWaitHandle)
+            {
+                if (result == workItemResults.Length)
+                {
+                    result = WaitHandle.WaitTimeout;
+                }
+            }
+
+            ReleaseWaitHandles(workItemResults);
+
+            return result;
+        }
+
+        /// <summary>
+        /// Fill an array of wait handles with the work items wait handles.
+        /// </summary>
+        /// <param name="workItemResults">An array of work item results</param>
+        /// <param name="waitHandles">An array of wait handles to fill</param>
+        private static void GetWaitHandles(
+            IWorkItemResult [] workItemResults,
+            WaitHandle [] waitHandles)
+        {
+            for(int i = 0; i < workItemResults.Length; ++i)
+            {
+                WorkItemResult wir = workItemResults[i] as WorkItemResult;
+                Debug.Assert(null != wir, "All workItemResults must be WorkItemResult objects");
+
+                waitHandles[i] = wir.GetWorkItem().GetWaitHandle();
+            }
+        }
+
+        /// <summary>
+        /// Release the work items' wait handles
+        /// </summary>
+        /// <param name="workItemResults">An array of work item results</param>
+        private static void ReleaseWaitHandles(IWorkItemResult [] workItemResults)
+        {
+            for(int i = 0; i < workItemResults.Length; ++i)
+            {
+                WorkItemResult wir = workItemResults[i] as WorkItemResult;
+
+                wir.GetWorkItem().ReleaseWaitHandle();
+            }
+        }
+
+
+        #endregion
+        
+        #region Private Members
+
+        private WorkItemState GetWorkItemState()
+        {
+            if (_canceledWorkItemsGroup.IsCanceled)
+            {
+                return WorkItemState.Canceled;
+            }
+            return _workItemState;
+
+        }
+        /// <summary>
+        /// Sets the work item's state
+        /// </summary>
+        /// <param name="workItemState">The state to set the work item to</param>
+        private void SetWorkItemState(WorkItemState workItemState)
+        {
+            lock(this)
+            {
+                _workItemState = workItemState;
+            }
+        }
+
+        /// <summary>
+        /// Signals that work item has been completed or canceled
+        /// </summary>
+        /// <param name="canceled">Indicates that the work item has been canceled</param>
+        private void SignalComplete(bool canceled)
+        {
+            SetWorkItemState(canceled ? WorkItemState.Canceled : WorkItemState.Completed);
+            lock(this)
+            {
+                // If someone is waiting then signal.
+                if (null != _workItemCompleted)
+                {
+                    _workItemCompleted.Set();
+                }
+            }
+        }
+
+        internal void WorkItemIsQueued()
+        {
+            _queuedTime = DateTime.Now;
+        }
+
+        #endregion
+        
+        #region Members exposed by WorkItemResult
+
+        /// <summary>
+        /// Cancel the work item if it didn't start running yet.
+        /// </summary>
+        /// <returns>Returns true on success or false if the work item is in progress or already completed</returns>
+        private bool Cancel()
+        {
+            lock(this)
+            {
+                switch(GetWorkItemState())
+                {
+                    case WorkItemState.Canceled:
+                        //Debug.WriteLine("Work item already canceled");
+                        return true;
+                    case WorkItemState.Completed:
+                    case WorkItemState.InProgress:
+                        //Debug.WriteLine("Work item cannot be canceled");
+                        return false;
+                    case WorkItemState.InQueue:
+                        // Signal to the wait for completion that the work
+                        // item has been completed (canceled). There is no
+                        // reason to wait for it to get out of the queue
+                        SignalComplete(true);
+                        //Debug.WriteLine("Work item canceled");
+                        return true;
+                }
+            }
+            return false;
+        }
+
+        /// <summary>
+        /// Get the result of the work item.
+        /// If the work item didn't run yet then the caller waits for the result, timeout, or cancel.
+        /// In case of error the method throws and exception
+        /// </summary>
+        /// <returns>The result of the work item</returns>
+        private object GetResult(
+            int millisecondsTimeout,
+            bool exitContext,
+            WaitHandle cancelWaitHandle)
+        {
+            Exception e = null;
+            object result = GetResult(millisecondsTimeout, exitContext, cancelWaitHandle, out e);
+            if (null != e)
+            {
+                throw new WorkItemResultException("The work item caused an excpetion, see the inner exception for details", e);
+            }
+            return result;
+        }
+
+        /// <summary>
+        /// Get the result of the work item.
+        /// If the work item didn't run yet then the caller waits for the result, timeout, or cancel.
+        /// In case of error the e argument is filled with the exception
+        /// </summary>
+        /// <returns>The result of the work item</returns>
+        private object GetResult(
+            int millisecondsTimeout,
+            bool exitContext,
+            WaitHandle cancelWaitHandle,
+            out Exception e)
+        {
+            e = null;
+
+            // Check for cancel
+            if (WorkItemState.Canceled == GetWorkItemState())
+            {
+                throw new WorkItemCancelException("Work item canceled");
+            }
+
+            // Check for completion
+            if (IsCompleted)
+            {
+                e = _exception;
+                return _result;
+            }
+
+            // If no cancelWaitHandle is provided
+            if (null == cancelWaitHandle)
+            {
+                WaitHandle wh = GetWaitHandle();
+
+                bool timeout = !wh.WaitOne(millisecondsTimeout, exitContext);
+
+                ReleaseWaitHandle();
+
+                if (timeout)
+                {
+                    throw new WorkItemTimeoutException("Work item timeout");
+                }
+            }
+            else
+            {
+                WaitHandle wh = GetWaitHandle();
+                int result = WaitHandle.WaitAny(new WaitHandle[] { wh, cancelWaitHandle });
+                ReleaseWaitHandle();
+
+                switch(result)
+                {
+                    case 0:
+                        // The work item signaled
+                        // Note that the signal could be also as a result of canceling the 
+                        // work item (not the get result)
+                        break;
+                    case 1:
+                    case WaitHandle.WaitTimeout:
+                        throw new WorkItemTimeoutException("Work item timeout");
+                    default:
+                        Debug.Assert(false);
+                        break;
+
+                }
+            }
+
+            // Check for cancel
+            if (WorkItemState.Canceled == GetWorkItemState())
+            {
+                throw new WorkItemCancelException("Work item canceled");
+            }
+
+            Debug.Assert(IsCompleted);
+
+            e = _exception;
+
+            // Return the result
+            return _result;
+        }
+
+        /// <summary>
+        /// A wait handle to wait for completion, cancel, or timeout 
+        /// </summary>
+        private WaitHandle GetWaitHandle()
+        {
+            lock(this)
+            {
+                if (null == _workItemCompleted)
+                {
+                    _workItemCompleted = new ManualResetEvent(IsCompleted);
+                }
+                ++_workItemCompletedRefCount;
+            }
+            return _workItemCompleted;
+        }
+
+        private void ReleaseWaitHandle()
+        {
+            lock(this)
+            {
+                if (null != _workItemCompleted)
+                {
+                    --_workItemCompletedRefCount;
+                    if (0 == _workItemCompletedRefCount)
+                    {
+                        _workItemCompleted.Close();
+                        _workItemCompleted = null;
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Returns true when the work item has completed or canceled
+        /// </summary>
+        private bool IsCompleted
+        {
+            get
+            {
+                lock(this)
+                {
+                    WorkItemState workItemState = GetWorkItemState();
+                    return ((workItemState == WorkItemState.Completed) || 
+                            (workItemState == WorkItemState.Canceled));
+                }
+            }
+        }
+
+        /// <summary>
+        /// Returns true when the work item has canceled
+        /// </summary>
+        public bool IsCanceled
+        {
+            get
+            {
+                lock(this)
+                {
+                    return (GetWorkItemState() == WorkItemState.Canceled);
+                }
+            }
+        }
+
+        #endregion
+
+        #region IHasWorkItemPriority Members
+
+        /// <summary>
+        /// Returns the priority of the work item
+        /// </summary>
+        public WorkItemPriority WorkItemPriority
+        {
+            get
+            {
+                return _workItemInfo.WorkItemPriority;
+            }
+        }
+
+        #endregion
+
+        internal event WorkItemStateCallback OnWorkItemStarted
+        {
+            add
+            {
+                _workItemStartedEvent += value;
+            }
+            remove
+            {
+                _workItemStartedEvent -= value;
+            }
+        }
+
+        internal event WorkItemStateCallback OnWorkItemCompleted
+        {
+            add
+            {
+                _workItemCompletedEvent += value;
+            }
+            remove
+            {
+                _workItemCompletedEvent -= value;
+            }
+        }
+
+
+        #region WorkItemResult class
+
+        private class WorkItemResult : IWorkItemResult, IInternalWorkItemResult
+        {
+            /// <summary>
+            /// A back reference to the work item
+            /// </summary>
+            private WorkItem _workItem;
+
+            public WorkItemResult(WorkItem workItem)
+            {
+                _workItem = workItem;
+            }
+
+            internal WorkItem GetWorkItem()
+            {
+                return _workItem;
+            }
+
+            #region IWorkItemResult Members
+
+            public bool IsCompleted
+            {
+                get
+                {
+                    return _workItem.IsCompleted;
+                }
+            }
+
+            public void Abort()
+            {
+                _workItem.Abort();
+            }
+
+            public bool IsCanceled
+            {
+                get
+                {
+                    return _workItem.IsCanceled;
+                }
+            }
+
+            public object GetResult()
+            {
+                return _workItem.GetResult(Timeout.Infinite, true, null);
+            }
+    
+            public object GetResult(int millisecondsTimeout, bool exitContext)
+            {
+                return _workItem.GetResult(millisecondsTimeout, exitContext, null);
+            }
+
+            public object GetResult(TimeSpan timeout, bool exitContext)
+            {
+                return _workItem.GetResult((int)timeout.TotalMilliseconds, exitContext, null);
+            }
+
+            public object GetResult(int millisecondsTimeout, bool exitContext, WaitHandle cancelWaitHandle)
+            {
+                return _workItem.GetResult(millisecondsTimeout, exitContext, cancelWaitHandle);
+            }
+
+            public object GetResult(TimeSpan timeout, bool exitContext, WaitHandle cancelWaitHandle)
+            {
+                return _workItem.GetResult((int)timeout.TotalMilliseconds, exitContext, cancelWaitHandle);
+            }
+
+            public object GetResult(out Exception e)
+            {
+                return _workItem.GetResult(Timeout.Infinite, true, null, out e);
+            }
+    
+            public object GetResult(int millisecondsTimeout, bool exitContext, out Exception e)
+            {
+                return _workItem.GetResult(millisecondsTimeout, exitContext, null, out e);
+            }
+
+            public object GetResult(TimeSpan timeout, bool exitContext, out Exception e)
+            {
+                return _workItem.GetResult((int)timeout.TotalMilliseconds, exitContext, null, out e);
+            }
+
+            public object GetResult(int millisecondsTimeout, bool exitContext, WaitHandle cancelWaitHandle, out Exception e)
+            {
+                return _workItem.GetResult(millisecondsTimeout, exitContext, cancelWaitHandle, out e);
+            }
+
+            public object GetResult(TimeSpan timeout, bool exitContext, WaitHandle cancelWaitHandle, out Exception e)
+            {
+                return _workItem.GetResult((int)timeout.TotalMilliseconds, exitContext, cancelWaitHandle, out e);
+            }
+
+            public bool Cancel()
+            {
+                return _workItem.Cancel();
+            }
+
+            public object State
+            {
+                get
+                {
+                    return _workItem._state;
+                }
+            }
+
+            public WorkItemPriority WorkItemPriority 
+            { 
+                get
+                {
+                    return _workItem._workItemInfo.WorkItemPriority;
+                }
+            }
+
+            /// <summary>
+            /// Return the result, same as GetResult()
+            /// </summary>
+            public object Result
+            {
+                get { return GetResult(); }
+            }
+
+            /// <summary>
+            /// Returns the exception if occured otherwise returns null.
+            /// This value is valid only after the work item completed,
+            /// before that it is always null.
+            /// </summary>
+            public object Exception
+            {
+                get { return _workItem._exception; }
+            }
+
+            #endregion
+
+            #region IInternalWorkItemResult Members
+
+            public event WorkItemStateCallback OnWorkItemStarted
+            {
+                add
+                {
+                    _workItem.OnWorkItemStarted += value;
+                }
+                remove
+                {
+                    _workItem.OnWorkItemStarted -= value;
+                }
+            }
+
+
+            public event WorkItemStateCallback OnWorkItemCompleted
+            {
+                add
+                {
+                    _workItem.OnWorkItemCompleted += value;
+                }
+                remove
+                {
+                    _workItem.OnWorkItemCompleted -= value;
+                }
+            }
+
+            #endregion
+        }
+
+        #endregion
+
+        public void DisposeOfState()
+        {
+            if (_workItemInfo.DisposeOfStateObjects)
+            {
+                IDisposable disp = _state as IDisposable;
+                if (null != disp)
+                {
+                    disp.Dispose();
+                    _state = null;
+                }
+            }
+        }
+
+        public void Abort()
+        {
+            lock (this)
+            {
+                if(currentThread != null)
+                    currentThread.Abort();
+            }
+        }
+    }
+    #endregion
+}