// 運用Monitor類同步線程示例
using System;
using System.Threading;
public class MonitorSample
{
   public static void Main(String[] args)
   {
      // result=0表示沒有發生異常，為1則表示發生異常
      int result = 0; 
      Cell cell = new Cell( );
      CellProd prod = new CellProd(cell, 5); 
      CellCons cons = new CellCons(cell, 5); 
      // 創建producer和consumer線程
      Thread producer = new Thread(new ThreadStart(prod.ThreadRun));
      Thread consumer = new Thread(new ThreadStart(cons.ThreadRun));
      try
      {
         producer.Start( );
         consumer.Start( );
         producer.Join( );
         consumer.Join( );  
      // 線程producer和consumer結束
      }
      catch (ThreadStateException e)
      {
         Console.WriteLine(e);  // 顯示異常信息
         result = 1; 
      }
      catch (ThreadInterruptedException e)
      {
         // 顯示線程在等待的時候被中斷的異常
         Console.WriteLine(e);
         result = 1;
      }
      Environment.ExitCode = result;
   }
}
public class CellProd
{
   Cell cell;         // 定義cell對象
   // quantity變量表示cell中產品的數量
   int quantity = 1;
   public CellProd(Cell box, int request)
   {
      cell = box; 
      quantity = request;
   }
   public void ThreadRun( )
   {
      for(int looper=1; looper<=quantity; looper++)
         cell.WriteToCell(looper);  
   }
}
public class CellCons
{
   Cell cell; 
   int quantity = 1;
   public CellCons(Cell box, int request)
   {
      cell = box; 
      quantity = request; 
   }
   public void ThreadRun( )
   {
      int valReturned;
      for(int looper=1; looper<=quantity; looper++)
      // 在valReturned中保存消耗數量
         valReturned=cell.ReadFromCell( );
   }
}
public class Cell
{
   int cellContents; 
   bool readerFlag = false; 
   public int ReadFromCell( )
   {
      lock(this)   // 進入同步塊
      {
         if (!readerFlag)
         {            // 等待直到Cell.WriteToCell處理完成
            try
            {
               // 等待Monitor.Pulse
               Monitor.Wait(this);
            }
            catch (SynchronizationLockException e)
            {
               Console.WriteLine(e);
            }
            catch (ThreadInterruptedException e)
            {
               Console.WriteLine(e);
            }
         }
         Console.WriteLine("消耗: {0}",cellContents);
         readerFlag = false; 
         // Pulse讓Cell.WriteToCell知道Cell.ReadFromCell已經完成
         Monitor.Pulse(this);   
      }   // 退出同步塊
      return cellContents;
   }
   public void WriteToCell(int n)
   {
      lock(this)  // 進入同步塊
      {
         if (readerFlag)
         { 
            try
            {
               Monitor.Wait(this); 
            }
            catch (SynchronizationLockException e)
            {
               Console.WriteLine(e);
            }
            catch (ThreadInterruptedException e)
            {
               Console.WriteLine(e);
            }
         }
         cellContents = n;
         Console.WriteLine("制造: {0}",cellContents);
         readerFlag = true;
         // Pulse讓Cell.ReadFromCell知道Cell.WriteToCell已經完成
         Monitor.Pulse(this); 
      }   // 退出同步塊
   }
}