.NET并行计算和并发6-获取线程池的最大可用线程数

 using System;
 using System.IO;
 using System.Security.Permissions;
 using System.Threading;
 
 class Test
 {
     static void Main()
     {
         AutoResetEvent mainEvent = new AutoResetEvent(false);
         int workerThreads;
         int portThreads;
 
         ThreadPool.GetMaxThreads(out workerThreads, out portThreads);
         Console.WriteLine("\nMaximum worker threads: \t{0}" +
             "\nMaximum completion port threads: {1}",
             workerThreads, portThreads);
 
         ThreadPool.GetAvailableThreads(out workerThreads,
             out portThreads);
         Console.WriteLine("\nAvailable worker threads: \t{0}" +
             "\nAvailable completion port threads: {1}\n",
             workerThreads, portThreads);
 
         ThreadPool.QueueUserWorkItem(new
             WaitCallback(ThreadPoolTest.WorkItemMethod), mainEvent);
 
         // Since ThreadPool threads are background threads,
         // wait for the work item to signal before ending Main.
         mainEvent.WaitOne(5000, false);
         Console.ReadLine();
     }
 }
 
 class ThreadPoolTest
 {
     // Maintains state information to be passed to EndWriteCallback.
     // This information allows the callback to end the asynchronous
     // write operation and signal when it is finished.
     class State
     {
         public FileStream fStream;
         public AutoResetEvent autoEvent;
 
         public State(FileStream fStream, AutoResetEvent autoEvent)
         {
             this.fStream = fStream;
             this.autoEvent = autoEvent;
         }
     }
 
     ThreadPoolTest() { }
 
     public static void WorkItemMethod(object mainEvent)
     {
         Console.WriteLine("\nStarting WorkItem.\n");
         AutoResetEvent autoEvent = new AutoResetEvent(false);
 
         // Create some data.
         const int ArraySize = 10000;
         const int BufferSize = 10000;
         byte[] byteArray = new Byte[ArraySize];
         new Random().NextBytes(byteArray);
 
         // Create two files and two State objects.
         FileStream fileWriter1 =
             new FileStream(@"C:\Test1@##.dat", FileMode.Create,
             FileAccess.ReadWrite, FileShare.ReadWrite,
             BufferSize, true);
         FileStream fileWriter2 =
             new FileStream(@"C:\Test2@##.dat", FileMode.Create,
             FileAccess.ReadWrite, FileShare.ReadWrite,
             BufferSize, true);
         State stateInfo1 = new State(fileWriter1, autoEvent);
         State stateInfo2 = new State(fileWriter2, autoEvent);
 
         // Asynchronously write to the files.
         fileWriter1.BeginWrite(byteArray, 0, byteArray.Length,
             new AsyncCallback(EndWriteCallback), stateInfo1);
         fileWriter2.BeginWrite(byteArray, 0, byteArray.Length,
             new AsyncCallback(EndWriteCallback), stateInfo2);
 
         // Wait for the callbacks to signal.
         autoEvent.WaitOne();
         autoEvent.WaitOne();
 
         fileWriter1.Close();
         fileWriter2.Close();
         Console.WriteLine("\nEnding WorkItem.\n");
 
         // Signal Main that the work item is finished.
         ((AutoResetEvent)mainEvent).Set();
     }
 
     static void EndWriteCallback(IAsyncResult asyncResult)
     {
         Console.WriteLine("Starting EndWriteCallback.");
 
         State stateInfo = (State)asyncResult.AsyncState;
         int workerThreads;
         int portThreads;
         try
         {
             ThreadPool.GetAvailableThreads(out workerThreads,
                 out portThreads);
             Console.WriteLine("\nAvailable worker threads: \t{0}" +
                 "\nAvailable completion port threads: {1}\n",
                 workerThreads, portThreads);
 
             stateInfo.fStream.EndWrite(asyncResult);
 
             // Sleep so the other thread has a chance to run
             // before the current thread ends.
             //Thread.Sleep(1500);
         }
         finally
         {
             // Signal that the current thread is finished.
             stateInfo.autoEvent.Set();
             Console.WriteLine("Ending EndWriteCallback.");
         }
     }
 }