C#任務調度——LimitedConcurrencyLevelTaskScheduler

• 這是參考大佬分享的代碼寫的有問題請提出指正，謝謝。

using Serilog;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;namespace TaskManager
{class TaskFactoryMananger{//USEpublic static void Run(){try{while (true){LimitedConcurrencyLevelTaskScheduler lcts = new LimitedConcurrencyLevelTaskScheduler(10);TaskFactory factory = new TaskFactory(lcts);Task[] spiderTask = new Task[] {factory.StartNew(() =>{Log.Logger.Information("{0} Start on thread {1}", "111", Thread.CurrentThread.ManagedThreadId);     Log.Logger.Information("{0} Finish  on thread {1}", "111", Thread.CurrentThread.ManagedThreadId);}),factory.StartNew(() =>{Thread.Sleep(TimeSpan.FromSeconds(3));Log.Logger.Information("{0} Start on thread {1}", "222", Thread.CurrentThread.ManagedThreadId);Log.Logger.Information("{0} Finish  on thread {1}", "222", Thread.CurrentThread.ManagedThreadId);}),factory.StartNew(() =>{Thread.Sleep(TimeSpan.FromSeconds(5));Log.Logger.Information("{0} Start on thread {1}", "333", Thread.CurrentThread.ManagedThreadId);Log.Logger.Information("{0} Finish  on thread {1}", "333", Thread.CurrentThread.ManagedThreadId);})};Task.WaitAll(spiderTask);Thread.Sleep(TimeSpan.FromMinutes(1));}}catch (AggregateException ex){foreach (Exception inner in ex.InnerExceptions){Log.Logger.Error(inner.Message);}}}/// <summary>/// Provides a task scheduler that ensures a maximum concurrency level while/// running on top of the ThreadPool./// </summary>public class LimitedConcurrencyLevelTaskScheduler : TaskScheduler{/// <summary>Whether the current thread is processing work items.</summary>[ThreadStatic]private static bool _currentThreadIsProcessingItems;/// <summary>The list of tasks to be executed.</summary>private readonly LinkedList<Task> _tasks = new LinkedList<Task>(); // protected by lock(_tasks)/// <summary>The maximum concurrency level allowed by this scheduler.</summary>private readonly int _maxDegreeOfParallelism;/// <summary>Whether the scheduler is currently processing work items.</summary>private int _delegatesQueuedOrRunning = 0; // protected by lock(_tasks)/// <summary>/// Initializes an instance of the LimitedConcurrencyLevelTaskScheduler class with the/// specified degree of parallelism./// </summary>/// <param name="maxDegreeOfParallelism">The maximum degree of parallelism provided by this scheduler.</param>public LimitedConcurrencyLevelTaskScheduler(int maxDegreeOfParallelism){if (maxDegreeOfParallelism < 1) throw new ArgumentOutOfRangeException("maxDegreeOfParallelism");_maxDegreeOfParallelism = maxDegreeOfParallelism;}/// <summary>Queues a task to the scheduler.</summary>/// <param name="task">The task to be queued.</param>protected sealed override void QueueTask(Task task){// Add the task to the list of tasks to be processed.  If there aren't enough// delegates currently queued or running to process tasks, schedule another.lock (_tasks){_tasks.AddLast(task);if (_delegatesQueuedOrRunning < _maxDegreeOfParallelism){++_delegatesQueuedOrRunning;NotifyThreadPoolOfPendingWork();}}}/// <summary>/// Informs the ThreadPool that there's work to be executed for this scheduler./// </summary>private void NotifyThreadPoolOfPendingWork(){ThreadPool.UnsafeQueueUserWorkItem(_ =>{// Note that the current thread is now processing work items.// This is necessary to enable inlining of tasks into this thread._currentThreadIsProcessingItems = true;try{// Process all available items in the queue.while (true){Task item;lock (_tasks){// When there are no more items to be processed,// note that we're done processing, and get out.if (_tasks.Count == 0){--_delegatesQueuedOrRunning;break;}// Get the next item from the queueitem = _tasks.First.Value;_tasks.RemoveFirst();}// Execute the task we pulled out of the queuebase.TryExecuteTask(item);}}// We're done processing items on the current threadfinally { _currentThreadIsProcessingItems = false; }}, null);}/// <summary>Attempts to execute the specified task on the current thread.</summary>/// <param name="task">The task to be executed.</param>/// <param name="taskWasPreviouslyQueued"></param>/// <returns>Whether the task could be executed on the current thread.</returns>protected sealed override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued){// If this thread isn't already processing a task, we don't support inliningif (!_currentThreadIsProcessingItems) return false;// If the task was previously queued, remove it from the queueif (taskWasPreviouslyQueued) TryDequeue(task);// Try to run the task.return base.TryExecuteTask(task);}/// <summary>Attempts to remove a previously scheduled task from the scheduler.</summary>/// <param name="task">The task to be removed.</param>/// <returns>Whether the task could be found and removed.</returns>protected sealed override bool TryDequeue(Task task){lock (_tasks) return _tasks.Remove(task);}/// <summary>Gets the maximum concurrency level supported by this scheduler.</summary>public sealed override int MaximumConcurrencyLevel { get { return _maxDegreeOfParallelism; } }/// <summary>Gets an enumerable of the tasks currently scheduled on this scheduler.</summary>/// <returns>An enumerable of the tasks currently scheduled.</returns>protected sealed override IEnumerable<Task> GetScheduledTasks(){bool lockTaken = false;try{Monitor.TryEnter(_tasks, ref lockTaken);if (lockTaken) return _tasks.ToArray();else throw new NotSupportedException();}finally{if (lockTaken) Monitor.Exit(_tasks);}}}}
}