// Ami Bar // amibar@gmail.com // // Smart thread pool in C#. // 7 Aug 2004 - Initial release // 14 Sep 2004 - Bug fixes // 15 Oct 2004 - Added new features // - Work items return result. // - Support waiting synchronization for multiple work items. // - Work items can be cancelled. // - Passage of the caller thread�s context to the thread in the pool. // - Minimal usage of WIN32 handles. // - Minor bug fixes. // 26 Dec 2004 - Changes: // - Removed static constructors. // - Added finalizers. // - Changed Exceptions so they are serializable. // - Fixed the bug in one of the SmartThreadPool constructors. // - Changed the SmartThreadPool.WaitAll() so it will support any number of waiters. // The SmartThreadPool.WaitAny() is still limited by the .NET Framework. // - Added PostExecute with options on which cases to call it. // - Added option to dispose of the state objects. // - Added a WaitForIdle() method that waits until the work items queue is empty. // - Added an STPStartInfo class for the initialization of the thread pool. // - Changed exception handling so if a work item throws an exception it // is rethrown at GetResult(), rather then firing an UnhandledException event. // Note that PostExecute exception are always ignored. // 25 Mar 2005 - Changes: // - Fixed lost of work items bug // 3 Jul 2005: Changes. // - Fixed bug where Enqueue() throws an exception because PopWaiter() returned null, hardly reconstructed. // 16 Aug 2005: Changes. // - Fixed bug where the InUseThreads becomes negative when canceling work items. // // 31 Jan 2006 - Changes: // - Added work items priority // - Removed support of chained delegates in callbacks and post executes (nobody really use this) // - Added work items groups // - Added work items groups idle event // - Changed SmartThreadPool.WaitAll() behavior so when it gets empty array // it returns true rather then throwing an exception. // - Added option to start the STP and the WIG as suspended // - Exception behavior changed, the real exception is returned by an // inner exception // - Added option to keep the Http context of the caller thread. (Thanks to Steven T.) // - Added performance counters // - Added priority to the threads in the pool // // 13 Feb 2006 - Changes: // - Added a call to the dispose of the Performance Counter so // their won't be a Performance Counter leak. // - Added exception catch in case the Performance Counters cannot // be created. using System; using System.Security; using System.Threading; using System.Collections; using System.Diagnostics; using System.Runtime.CompilerServices; using Amib.Threading.Internal; namespace Amib.Threading { #region SmartThreadPool class /// <summary> /// Smart thread pool class. /// </summary> public class SmartThreadPool : IWorkItemsGroup, IDisposable { #region Default Constants /// <summary> /// Default minimum number of threads the thread pool contains. (0) /// </summary> public const int DefaultMinWorkerThreads = 0; /// <summary> /// Default maximum number of threads the thread pool contains. (25) /// </summary> public const int DefaultMaxWorkerThreads = 25; /// <summary> /// Default idle timeout in milliseconds. (One minute) /// </summary> public const int DefaultIdleTimeout = 60*1000; // One minute /// <summary> /// Indicate to copy the security context of the caller and then use it in the call. (false) /// </summary> public const bool DefaultUseCallerCallContext = false; /// <summary> /// Indicate to copy the HTTP context of the caller and then use it in the call. (false) /// </summary> public const bool DefaultUseCallerHttpContext = false; /// <summary> /// Indicate to dispose of the state objects if they support the IDispose interface. (false) /// </summary> public const bool DefaultDisposeOfStateObjects = false; /// <summary> /// The default option to run the post execute /// </summary> public const CallToPostExecute DefaultCallToPostExecute = CallToPostExecute.Always; /// <summary> /// The default post execute method to run. /// When null it means not to call it. /// </summary> public static readonly PostExecuteWorkItemCallback DefaultPostExecuteWorkItemCallback = null; /// <summary> /// The default work item priority /// </summary> public const WorkItemPriority DefaultWorkItemPriority = WorkItemPriority.Normal; /// <summary> /// The default is to work on work items as soon as they arrive /// and not to wait for the start. /// </summary> public const bool DefaultStartSuspended = false; /// <summary> /// The default is not to use the performance counters /// </summary> public static readonly string DefaultPerformanceCounterInstanceName = null; public static readonly int DefaultStackSize = 0; /// <summary> /// The default thread priority /// </summary> public const ThreadPriority DefaultThreadPriority = ThreadPriority.Normal; #endregion #region Member Variables /// <summary> /// Contains the name of this instance of SmartThreadPool. /// Can be changed by the user. /// </summary> private string _name = "SmartThreadPool"; /// <summary> /// Hashtable of all the threads in the thread pool. /// </summary> private Hashtable _workerThreads = Hashtable.Synchronized(new Hashtable()); /// <summary> /// Queue of work items. /// </summary> private WorkItemsQueue _workItemsQueue = new WorkItemsQueue(); /// <summary> /// Count the work items handled. /// Used by the performance counter. /// </summary> private long _workItemsProcessed = 0; /// <summary> /// Number of threads that currently work (not idle). /// </summary> private int _inUseWorkerThreads = 0; /// <summary> /// Start information to use. /// It is simpler than providing many constructors. /// </summary> private STPStartInfo _stpStartInfo = new STPStartInfo(); /// <summary> /// Total number of work items that are stored in the work items queue /// plus the work items that the threads in the pool are working on. /// </summary> private int _currentWorkItemsCount = 0; /// <summary> /// Signaled when the thread pool is idle, i.e. no thread is busy /// and the work items queue is empty /// </summary> private ManualResetEvent _isIdleWaitHandle = new ManualResetEvent(true); /// <summary> /// An event to signal all the threads to quit immediately. /// </summary> private ManualResetEvent _shuttingDownEvent = new ManualResetEvent(false); /// <summary> /// A flag to indicate the threads to quit. /// </summary> private bool _shutdown = false; /// <summary> /// Counts the threads created in the pool. /// It is used to name the threads. /// </summary> private int _threadCounter = 0; /// <summary> /// Indicate that the SmartThreadPool has been disposed /// </summary> private bool _isDisposed = false; /// <summary> /// Event to send that the thread pool is idle /// </summary> private event EventHandler _stpIdle; /// <summary> /// On idle event /// </summary> //private event WorkItemsGroupIdleHandler _onIdle; /// <summary> /// Holds all the WorkItemsGroup instaces that have at least one /// work item int the SmartThreadPool /// This variable is used in case of Shutdown /// </summary> private Hashtable _workItemsGroups = Hashtable.Synchronized(new Hashtable()); /// <summary> /// A reference from each thread in the thread pool to its SmartThreadPool /// object container. /// With this variable a thread can know whatever it belongs to a /// SmartThreadPool. /// </summary> [ThreadStatic] private static SmartThreadPool _smartThreadPool; /// <summary> /// A reference to the current work item a thread from the thread pool /// is executing. /// </summary> [ThreadStatic] private static WorkItem _currentWorkItem; /// <summary> /// STP performance counters /// </summary> private ISTPInstancePerformanceCounters _pcs = NullSTPInstancePerformanceCounters.Instance; #endregion #region Construction and Finalization /// <summary> /// Constructor /// </summary> public SmartThreadPool() { Initialize(); } /// <summary> /// Constructor /// </summary> /// <param name="idleTimeout">Idle timeout in milliseconds</param> public SmartThreadPool(int idleTimeout) { _stpStartInfo.IdleTimeout = idleTimeout; Initialize(); } /// <summary> /// Constructor /// </summary> /// <param name="idleTimeout">Idle timeout in milliseconds</param> /// <param name="maxWorkerThreads">Upper limit of threads in the pool</param> public SmartThreadPool( int idleTimeout, int maxWorkerThreads) { _stpStartInfo.IdleTimeout = idleTimeout; _stpStartInfo.MaxWorkerThreads = maxWorkerThreads; Initialize(); } /// <summary> /// Constructor /// </summary> /// <param name="idleTimeout">Idle timeout in milliseconds</param> /// <param name="maxWorkerThreads">Upper limit of threads in the pool</param> /// <param name="minWorkerThreads">Lower limit of threads in the pool</param> public SmartThreadPool( int idleTimeout, int maxWorkerThreads, int minWorkerThreads) { _stpStartInfo.IdleTimeout = idleTimeout; _stpStartInfo.MaxWorkerThreads = maxWorkerThreads; _stpStartInfo.MinWorkerThreads = minWorkerThreads; Initialize(); } /// <summary> /// Constructor /// </summary> public SmartThreadPool(STPStartInfo stpStartInfo) { _stpStartInfo = new STPStartInfo(stpStartInfo); Initialize(); } private void Initialize() { ValidateSTPStartInfo(); if (null != _stpStartInfo.PerformanceCounterInstanceName) { try { _pcs = new STPInstancePerformanceCounters(_stpStartInfo.PerformanceCounterInstanceName); } catch(Exception e) { Debug.WriteLine("Unable to create Performance Counters: " + e.ToString()); _pcs = NullSTPInstancePerformanceCounters.Instance; } } StartOptimalNumberOfThreads(); } private void StartOptimalNumberOfThreads() { int threadsCount = Math.Max(_workItemsQueue.Count, _stpStartInfo.MinWorkerThreads); threadsCount = Math.Min(threadsCount, _stpStartInfo.MaxWorkerThreads); StartThreads(threadsCount); } private void ValidateSTPStartInfo() { if (_stpStartInfo.MinWorkerThreads < 0) { throw new ArgumentOutOfRangeException( "MinWorkerThreads", "MinWorkerThreads cannot be negative"); } if (_stpStartInfo.MaxWorkerThreads <= 0) { throw new ArgumentOutOfRangeException( "MaxWorkerThreads", "MaxWorkerThreads must be greater than zero"); } if (_stpStartInfo.MinWorkerThreads > _stpStartInfo.MaxWorkerThreads) { throw new ArgumentOutOfRangeException( "MinWorkerThreads, maxWorkerThreads", "MaxWorkerThreads must be greater or equal to MinWorkerThreads"); } } private void ValidateCallback(Delegate callback) { if(callback.GetInvocationList().Length > 1) { throw new NotSupportedException("SmartThreadPool doesn't support delegates chains"); } } #endregion #region Thread Processing /// <summary> /// Waits on the queue for a work item, shutdown, or timeout. /// </summary> /// <returns> /// Returns the WaitingCallback or null in case of timeout or shutdown. /// </returns> private WorkItem Dequeue() { WorkItem workItem = _workItemsQueue.DequeueWorkItem(_stpStartInfo.IdleTimeout, _shuttingDownEvent); return workItem; } /// <summary> /// Put a new work item in the queue /// </summary> /// <param name="workItem">A work item to queue</param> private void Enqueue(WorkItem workItem) { Enqueue(workItem, true); } /// <summary> /// Put a new work item in the queue /// </summary> /// <param name="workItem">A work item to queue</param> internal void Enqueue(WorkItem workItem, bool incrementWorkItems) { // Make sure the workItem is not null Debug.Assert(null != workItem); if (incrementWorkItems) { IncrementWorkItemsCount(); } _workItemsQueue.EnqueueWorkItem(workItem); workItem.WorkItemIsQueued(); // If all the threads are busy then try to create a new one if ((InUseThreads + WaitingCallbacks) > _workerThreads.Count) { StartThreads(1); } } private void IncrementWorkItemsCount() { _pcs.SampleWorkItems(_workItemsQueue.Count, _workItemsProcessed); int count = Interlocked.Increment(ref _currentWorkItemsCount); //Trace.WriteLine("WorkItemsCount = " + _currentWorkItemsCount.ToString()); if (count == 1) { //Trace.WriteLine("STP is NOT idle"); _isIdleWaitHandle.Reset(); } } private void DecrementWorkItemsCount() { ++_workItemsProcessed; // The counter counts even if the work item was cancelled _pcs.SampleWorkItems(_workItemsQueue.Count, _workItemsProcessed); int count = Interlocked.Decrement(ref _currentWorkItemsCount); //Trace.WriteLine("WorkItemsCount = " + _currentWorkItemsCount.ToString()); if (count == 0) { //Trace.WriteLine("STP is idle"); _isIdleWaitHandle.Set(); } } internal void RegisterWorkItemsGroup(IWorkItemsGroup workItemsGroup) { _workItemsGroups[workItemsGroup] = workItemsGroup; } internal void UnregisterWorkItemsGroup(IWorkItemsGroup workItemsGroup) { if (_workItemsGroups.Contains(workItemsGroup)) { _workItemsGroups.Remove(workItemsGroup); } } /// <summary> /// Inform that the current thread is about to quit or quiting. /// The same thread may call this method more than once. /// </summary> private void InformCompleted() { // There is no need to lock the two methods together // since only the current thread removes itself // and the _workerThreads is a synchronized hashtable if (_workerThreads.Contains(Thread.CurrentThread)) { _workerThreads.Remove(Thread.CurrentThread); _pcs.SampleThreads(_workerThreads.Count, _inUseWorkerThreads); } } /// <summary> /// Starts new threads /// </summary> /// <param name="threadsCount">The number of threads to start</param> private void StartThreads(int threadsCount) { if (_stpStartInfo.StartSuspended) { return; } lock(_workerThreads.SyncRoot) { // Don't start threads on shut down if (_shutdown) { return; } for(int i = 0; i < threadsCount; ++i) { // Don't create more threads then the upper limit if (_workerThreads.Count >= _stpStartInfo.MaxWorkerThreads) { return; } // Create a new thread Thread workerThread; if (_stpStartInfo.StackSize > 0) workerThread = new Thread(ProcessQueuedItems, _stpStartInfo.StackSize); else workerThread = new Thread(ProcessQueuedItems); // Configure the new thread and start it workerThread.Name = "STP " + Name + " Thread #" + _threadCounter; workerThread.IsBackground = true; workerThread.Priority = _stpStartInfo.ThreadPriority; workerThread.Start(); ++_threadCounter; // Add the new thread to the hashtable and update its creation // time. _workerThreads[workerThread] = DateTime.Now; _pcs.SampleThreads(_workerThreads.Count, _inUseWorkerThreads); } } } /// <summary> /// A worker thread method that processes work items from the work items queue. /// </summary> private void ProcessQueuedItems() { // Initialize the _smartThreadPool variable _smartThreadPool = this; try { bool bInUseWorkerThreadsWasIncremented = false; // Process until shutdown. while(!_shutdown) { // Wait for a work item, shutdown, or timeout WorkItem workItem = Dequeue(); // On timeout or shut down. if (null == workItem) { // Double lock for quit. if (_workerThreads.Count > _stpStartInfo.MinWorkerThreads) { lock(_workerThreads.SyncRoot) { // Update the last time this thread was seen alive. // It's good for debugging. _workerThreads[Thread.CurrentThread] = DateTime.Now; if (_workerThreads.Count > _stpStartInfo.MinWorkerThreads) { // Inform that the thread is quiting and then quit. // This method must be called within this lock or else // more threads will quit and the thread pool will go // below the lower limit. InformCompleted(); break; } } } } // If we didn't quit then skip to the next iteration. if (null == workItem) { continue; } try { // Initialize the value to false bInUseWorkerThreadsWasIncremented = false; // Change the state of the work item to 'in progress' if possible. // We do it here so if the work item has been canceled we won't // increment the _inUseWorkerThreads. // The cancel mechanism doesn't delete items from the queue, // it marks the work item as canceled, and when the work item // is dequeued, we just skip it. // If the post execute of work item is set to always or to // call when the work item is canceled then the StartingWorkItem() // will return true, so the post execute can run. if (!workItem.StartingWorkItem()) { continue; } // Execute the callback. Make sure to accurately // record how many callbacks are currently executing. int inUseWorkerThreads = Interlocked.Increment(ref _inUseWorkerThreads); _pcs.SampleThreads(_workerThreads.Count, inUseWorkerThreads); // Mark that the _inUseWorkerThreads incremented, so in the finally{} // statement we will decrement it correctly. bInUseWorkerThreadsWasIncremented = true; // Set the _currentWorkItem to the current work item _currentWorkItem = workItem; lock(workItem) { workItem.currentThread = Thread.CurrentThread; } ExecuteWorkItem(workItem); lock(workItem) { workItem.currentThread = null; } } catch(ThreadAbortException ex) { lock(workItem) { workItem.currentThread = null; } ex.GetHashCode(); Thread.ResetAbort(); } catch(Exception ex) { ex.GetHashCode(); // Do nothing } finally { lock(workItem) { workItem.currentThread = null; } if (null != workItem) { workItem.DisposeOfState(); } // Set the _currentWorkItem to null, since we // no longer run user's code. _currentWorkItem = null; // Decrement the _inUseWorkerThreads only if we had // incremented it. Note the cancelled work items don't // increment _inUseWorkerThreads. if (bInUseWorkerThreadsWasIncremented) { int inUseWorkerThreads = Interlocked.Decrement(ref _inUseWorkerThreads); _pcs.SampleThreads(_workerThreads.Count, inUseWorkerThreads); } // Notify that the work item has been completed. // WorkItemsGroup may enqueue their next work item. workItem.FireWorkItemCompleted(); // Decrement the number of work items here so the idle // ManualResetEvent won't fluctuate. DecrementWorkItemsCount(); } } } catch(ThreadAbortException tae) { tae.GetHashCode(); // Handle the abort exception gracfully. Thread.ResetAbort(); } catch(Exception e) { Debug.Assert(null != e); } finally { InformCompleted(); } } private void ExecuteWorkItem(WorkItem workItem) { _pcs.SampleWorkItemsWaitTime(workItem.WaitingTime); try { workItem.Execute(); } catch { throw; } finally { _pcs.SampleWorkItemsProcessTime(workItem.ProcessTime); } } #endregion #region Public Methods /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem(WorkItemCallback callback) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="workItemPriority">The priority of the work item</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem(WorkItemCallback callback, WorkItemPriority workItemPriority) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, workItemPriority); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="workItemInfo">Work item info</param> /// <param name="callback">A callback to execute</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem(WorkItemInfo workItemInfo, WorkItemCallback callback) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, workItemInfo, callback); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, state); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <param name="workItemPriority">The work item priority</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem(WorkItemCallback callback, object state, WorkItemPriority workItemPriority) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, state, workItemPriority); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="workItemInfo">Work item information</param> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem(WorkItemInfo workItemInfo, WorkItemCallback callback, object state) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, workItemInfo, callback, state); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <param name="postExecuteWorkItemCallback"> /// A delegate to call after the callback completion /// </param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem( WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, state, postExecuteWorkItemCallback); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <param name="postExecuteWorkItemCallback"> /// A delegate to call after the callback completion /// </param> /// <param name="workItemPriority">The work item priority</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem( WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback, WorkItemPriority workItemPriority) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, state, postExecuteWorkItemCallback, workItemPriority); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <param name="postExecuteWorkItemCallback"> /// A delegate to call after the callback completion /// </param> /// <param name="callToPostExecute">Indicates on which cases to call to the post execute callback</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem( WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback, CallToPostExecute callToPostExecute) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, state, postExecuteWorkItemCallback, callToPostExecute); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Queue a work item /// </summary> /// <param name="callback">A callback to execute</param> /// <param name="state"> /// The context object of the work item. Used for passing arguments to the work item. /// </param> /// <param name="postExecuteWorkItemCallback"> /// A delegate to call after the callback completion /// </param> /// <param name="callToPostExecute">Indicates on which cases to call to the post execute callback</param> /// <param name="workItemPriority">The work item priority</param> /// <returns>Returns a work item result</returns> public IWorkItemResult QueueWorkItem( WorkItemCallback callback, object state, PostExecuteWorkItemCallback postExecuteWorkItemCallback, CallToPostExecute callToPostExecute, WorkItemPriority workItemPriority) { ValidateNotDisposed(); ValidateCallback(callback); WorkItem workItem = WorkItemFactory.CreateWorkItem(this, _stpStartInfo, callback, state, postExecuteWorkItemCallback, callToPostExecute, workItemPriority); Enqueue(workItem); return workItem.GetWorkItemResult(); } /// <summary> /// Wait for the thread pool to be idle /// </summary> public void WaitForIdle() { WaitForIdle(Timeout.Infinite); } /// <summary> /// Wait for the thread pool to be idle /// </summary> public bool WaitForIdle(TimeSpan timeout) { return WaitForIdle((int)timeout.TotalMilliseconds); } /// <summary> /// Wait for the thread pool to be idle /// </summary> public bool WaitForIdle(int millisecondsTimeout) { ValidateWaitForIdle(); return _isIdleWaitHandle.WaitOne(millisecondsTimeout, false); } private void ValidateWaitForIdle() { if(_smartThreadPool == this) { throw new NotSupportedException( "WaitForIdle cannot be called from a thread on its SmartThreadPool, it will cause may cause a deadlock"); } } internal void ValidateWorkItemsGroupWaitForIdle(IWorkItemsGroup workItemsGroup) { ValidateWorkItemsGroupWaitForIdleImpl(workItemsGroup, SmartThreadPool._currentWorkItem); if ((null != workItemsGroup) && (null != SmartThreadPool._currentWorkItem) && SmartThreadPool._currentWorkItem.WasQueuedBy(workItemsGroup)) { throw new NotSupportedException("WaitForIdle cannot be called from a thread on its SmartThreadPool, it will cause may cause a deadlock"); } } [MethodImpl(MethodImplOptions.NoInlining)] private void ValidateWorkItemsGroupWaitForIdleImpl(IWorkItemsGroup workItemsGroup, WorkItem workItem) { if ((null != workItemsGroup) && (null != workItem) && workItem.WasQueuedBy(workItemsGroup)) { throw new NotSupportedException("WaitForIdle cannot be called from a thread on its SmartThreadPool, it will cause may cause a deadlock"); } } /// <summary> /// Force the SmartThreadPool to shutdown /// </summary> public void Shutdown() { Shutdown(true, 0); } public void Shutdown(bool forceAbort, TimeSpan timeout) { Shutdown(forceAbort, (int)timeout.TotalMilliseconds); } /// <summary> /// Empties the queue of work items and abort the threads in the pool. /// </summary> public void Shutdown(bool forceAbort, int millisecondsTimeout) { ValidateNotDisposed(); ISTPInstancePerformanceCounters pcs = _pcs; if (NullSTPInstancePerformanceCounters.Instance != _pcs) { _pcs.Dispose(); // Set the _pcs to "null" to stop updating the performance // counters _pcs = NullSTPInstancePerformanceCounters.Instance; } Thread [] threads = null; lock(_workerThreads.SyncRoot) { // Shutdown the work items queue _workItemsQueue.Dispose(); // Signal the threads to exit _shutdown = true; _shuttingDownEvent.Set(); // Make a copy of the threads' references in the pool threads = new Thread [_workerThreads.Count]; _workerThreads.Keys.CopyTo(threads, 0); } int millisecondsLeft = millisecondsTimeout; DateTime start = DateTime.Now; bool waitInfinitely = (Timeout.Infinite == millisecondsTimeout); bool timeout = false; // Each iteration we update the time left for the timeout. foreach(Thread thread in threads) { // Join don't work with negative numbers if (!waitInfinitely && (millisecondsLeft < 0)) { timeout = true; break; } // Wait for the thread to terminate bool success = thread.Join(millisecondsLeft); if(!success) { timeout = true; break; } if(!waitInfinitely) { // Update the time left to wait TimeSpan ts = DateTime.Now - start; millisecondsLeft = millisecondsTimeout - (int)ts.TotalMilliseconds; } } if (timeout && forceAbort) { // Abort the threads in the pool foreach(Thread thread in threads) { if ((thread != null) && thread.IsAlive) { try { thread.Abort("Shutdown"); } catch(SecurityException e) { e.GetHashCode(); } catch(ThreadStateException ex) { ex.GetHashCode(); // In case the thread has been terminated // after the check if it is alive. } } } } // Dispose of the performance counters pcs.Dispose(); } /// <summary> /// Wait for all work items to complete /// </summary> /// <param name="workItemResults">Array of work item result objects</param> /// <returns> /// true when every work item in workItemResults has completed; otherwise false. /// </returns> public static bool WaitAll( IWorkItemResult [] workItemResults) { return WaitAll(workItemResults, Timeout.Infinite, true); } /// <summary> /// Wait for all work items to complete /// </summary> /// <param name="workItemResults">Array of work item result objects</param> /// <param name="timeout">The number of milliseconds to wait, or a TimeSpan that represents -1 milliseconds 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> /// <returns> /// true when every work item in workItemResults has completed; otherwise false. /// </returns> public static bool WaitAll( IWorkItemResult [] workItemResults, TimeSpan timeout, bool exitContext) { return WaitAll(workItemResults, (int)timeout.TotalMilliseconds, exitContext); } /// <summary> /// Wait for all work items to complete /// </summary> /// <param name="workItemResults">Array of work item result objects</param> /// <param name="timeout">The number of milliseconds to wait, or a TimeSpan that represents -1 milliseconds 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> public static bool WaitAll( IWorkItemResult [] workItemResults, TimeSpan timeout, bool exitContext, WaitHandle cancelWaitHandle) { return WaitAll(workItemResults, (int)timeout.TotalMilliseconds, exitContext, cancelWaitHandle); } /// <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> /// <returns> /// true when every work item in workItemResults has completed; otherwise false. /// </returns> public static bool WaitAll( IWorkItemResult [] workItemResults, int millisecondsTimeout, bool exitContext) { return WorkItem.WaitAll(workItemResults, millisecondsTimeout, exitContext, null); } /// <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> public static bool WaitAll( IWorkItemResult [] workItemResults, int millisecondsTimeout, bool exitContext, WaitHandle cancelWaitHandle) { return WorkItem.WaitAll(workItemResults, millisecondsTimeout, exitContext, cancelWaitHandle); } /// <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> /// <returns> /// The array index of the work item result that satisfied the wait, or WaitTimeout if any of the work items has been canceled. /// </returns> public static int WaitAny( IWorkItemResult [] workItemResults) { return WaitAny(workItemResults, Timeout.Infinite, true); } /// <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="timeout">The number of milliseconds to wait, or a TimeSpan that represents -1 milliseconds 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> /// <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> public static int WaitAny( IWorkItemResult [] workItemResults, TimeSpan timeout, bool exitContext) { return WaitAny(workItemResults, (int)timeout.TotalMilliseconds, exitContext); } /// <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="timeout">The number of milliseconds to wait, or a TimeSpan that represents -1 milliseconds 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> public static int WaitAny( IWorkItemResult [] workItemResults, TimeSpan timeout, bool exitContext, WaitHandle cancelWaitHandle) { return WaitAny(workItemResults, (int)timeout.TotalMilliseconds, exitContext, cancelWaitHandle); } /// <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> /// <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> public static int WaitAny( IWorkItemResult [] workItemResults, int millisecondsTimeout, bool exitContext) { return WorkItem.WaitAny(workItemResults, millisecondsTimeout, exitContext, null); } /// <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> public static int WaitAny( IWorkItemResult [] workItemResults, int millisecondsTimeout, bool exitContext, WaitHandle cancelWaitHandle) { return WorkItem.WaitAny(workItemResults, millisecondsTimeout, exitContext, cancelWaitHandle); } public IWorkItemsGroup CreateWorkItemsGroup(int concurrency) { IWorkItemsGroup workItemsGroup = new WorkItemsGroup(this, concurrency, _stpStartInfo); return workItemsGroup; } public IWorkItemsGroup CreateWorkItemsGroup(int concurrency, WIGStartInfo wigStartInfo) { IWorkItemsGroup workItemsGroup = new WorkItemsGroup(this, concurrency, wigStartInfo); return workItemsGroup; } public event WorkItemsGroupIdleHandler OnIdle { add { throw new NotImplementedException("This event is not implemented in the SmartThreadPool class. Please create a WorkItemsGroup in order to use this feature."); //_onIdle += value; } remove { throw new NotImplementedException("This event is not implemented in the SmartThreadPool class. Please create a WorkItemsGroup in order to use this feature."); //_onIdle -= value; } } public void Cancel() { ICollection workItemsGroups = _workItemsGroups.Values; foreach(WorkItemsGroup workItemsGroup in workItemsGroups) { workItemsGroup.Cancel(); } } public void Start() { lock (this) { if (!this._stpStartInfo.StartSuspended) { return; } _stpStartInfo.StartSuspended = false; } ICollection workItemsGroups = _workItemsGroups.Values; foreach(WorkItemsGroup workItemsGroup in workItemsGroups) { workItemsGroup.OnSTPIsStarting(); } StartOptimalNumberOfThreads(); } #endregion #region Properties /// <summary> /// Get/Set the name of the SmartThreadPool instance /// </summary> public string Name { get { return _name; } set { _name = value; } } /// <summary> /// Get the lower limit of threads in the pool. /// </summary> public int MinThreads { get { ValidateNotDisposed(); return _stpStartInfo.MinWorkerThreads; } } /// <summary> /// Get the upper limit of threads in the pool. /// </summary> public int MaxThreads { get { ValidateNotDisposed(); return _stpStartInfo.MaxWorkerThreads; } } /// <summary> /// Get the number of threads in the thread pool. /// Should be between the lower and the upper limits. /// </summary> public int ActiveThreads { get { ValidateNotDisposed(); return _workerThreads.Count; } } /// <summary> /// Get the number of busy (not idle) threads in the thread pool. /// </summary> public int InUseThreads { get { ValidateNotDisposed(); return _inUseWorkerThreads; } } /// <summary> /// Get the number of work items in the queue. /// </summary> public int WaitingCallbacks { get { ValidateNotDisposed(); return _workItemsQueue.Count; } } public event EventHandler Idle { add { _stpIdle += value; } remove { _stpIdle -= value; } } #endregion #region IDisposable Members // ~SmartThreadPool() // { // Dispose(); // } public void Dispose() { if (!_isDisposed) { if (!_shutdown) { Shutdown(); } if (null != _shuttingDownEvent) { _shuttingDownEvent.Close(); _shuttingDownEvent = null; } _workerThreads.Clear(); _isDisposed = true; GC.SuppressFinalize(this); } } private void ValidateNotDisposed() { if(_isDisposed) { throw new ObjectDisposedException(GetType().ToString(), "The SmartThreadPool has been shutdown"); } } #endregion } #endregion }