C#多线程同步问题---使用Monitor类

   1: using System;

   2: using System.Collections.Generic;

   3: using System.Linq;

   4: using System.Text;

   5: using System.Threading;

   6: using System.Threading.Tasks;

   7:  

   8: namespace SynchronizationSamples

   9: {

  10:     public class SharedState

  11:     {

  12:         private int state = 0;

  13:         private object syncRoot = new object();

  14:         public int State 

  15:         { 

  16:             get{return state;}

  17:             set { state = value; }

  18:         }

  19:  

  20:         public int IncrementState()

  21:         {

  22:             bool lockTaken = false;

  23:             Monitor.TryEnter(syncRoot, 500, ref lockTaken);

  24:             if (lockTaken)

  25:             {

  26:                 try

  27:                 {

  28:                     return ++state;

  29:                 }

  30:                 finally

  31:                 {

  32:                     Monitor.Exit(syncRoot);

  33:                 }

  34:             }

  35:             else

  36:             {

  37:                 return state;

  38:             }

  39:         }

  40:     }

  41:  

  42:     public class Job

  43:     {

  44:         SharedState sharedState;

  45:         public Job(SharedState sharedState)

  46:         {

  47:             this.sharedState = sharedState;

  48:         }

  49:  

  50:         public void DoTheJob()

  51:         {

  52:             for (int i = 0; i < 50000;i++ )

  53:             {

  54:                 sharedState.IncrementState();

  55:             }

  56:         }

  57:     }

  58:     class Program

  59:     {

  60:         static void Main(string[] args)

  61:         {

  62:             int numTasks = 20;

  63:             var state = new SharedState();

  64:             var tasks = new Task[numTasks];

  65:  

  66:             for (int i = 0; i < numTasks; i++)

  67:             {

  68:                 tasks[i] = new Task(new Job(state).DoTheJob);

  69:                 tasks[i].Start();

  70:             }

  71:  

  72:             for (int i = 0; i < numTasks;i++ )

  73:             {

  74:                 tasks[i].Wait();

  75:             }

  76:             Console.WriteLine("summarized {0}",state.State);

  77:             Console.Read();

  78:         }

  79:     }

  80: }