关于“GUI 博士的忠告：切勿锁定类型对象！”的实验

  1using System;
  2using System.Threading;
  3
  4namespace TestLab.System.Threading
  5{
  6    //在遇到线程类问题的时候，我们需要注意：
  7    //a线程在执行“代码中连续的语句”a1、a2时，并不代表他们在实际执行时也是连续了(也许是连续的也许不是)
  8    //也就是说此时b线程完全有可能在a1、a2之间做“小三”，这是上帝（CPU）的意思
  9    internal class LowThread1
 10    {
 11        private static int _data;
 12        private static object _lockObj = new object();
 13        private string _name;
 14
 15        public int Data
 16        {
 17            get { return _data; }
 18        }
 19
 20        public LowThread1(string name)
 21        {
 22            this._name = name;
 23            Console.WriteLine("{1}创建新的LowLevel1对象:{0}", name, DateTime.Now);
 24        }
 25
 26        public void FightOver1()
 27        {
 28            Console.WriteLine("{1}方法名:FightOver1------{0}", this._name, DateTime.Now);
 29            Console.WriteLine("{2}线程名:{0}------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 30            Console.WriteLine("{1}正在抢夺操作------{0}", this._name, DateTime.Now);
 31
 32            lock (_lockObj)
 33            {
 34                Console.WriteLine("{2}线程名:{0} 开始操作资源.------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 35                _data++;
 36                Console.WriteLine("{2}操作完毕，现在的数据值:{0}------{1}", _data, this._name, DateTime.Now);
 37                Console.WriteLine("{1}开始Sleep 5 秒------{0}", this._name, DateTime.Now);
 38                Thread.Sleep(5000);
 39            }
 40
 41            Console.WriteLine("{2}线程名:{0} 已经离开操作------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 42        }
 43        public void FightOver2()
 44        {
 45            Console.WriteLine("{1}方法名:FightOver1------{0}", this._name, DateTime.Now);
 46            Console.WriteLine("{2}线程名:{0}------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 47            Console.WriteLine("{1}正在抢夺操作------{0}", this._name, DateTime.Now);
 48
 49            lock(typeof(LowThread1))
 50            {
 51                Console.WriteLine("{2}线程:{0} 在LowLevel1.FightOver2()中开始睡 5 秒------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 52                Thread.Sleep(5000);
 53            }
 54            Console.WriteLine("{2}线程名:{0} 已经离开操作------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 55        }
 56        public void FightOver3_1()
 57        {
 58            Console.WriteLine("{1}方法名:FightOver1------{0}", this._name, DateTime.Now);
 59            Console.WriteLine("{2}线程名:{0}------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 60            Console.WriteLine("{1}正在抢夺操作------{0}", this._name, DateTime.Now);
 61
 62            lock (this)
 63            {
 64                Console.WriteLine("{2}线程:{0} 在LowLevel1.FightOver2()中开始睡 5 秒------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 65                Thread.Sleep(5000);
 66            }
 67            Console.WriteLine("{2}线程名:{0} 已经离开操作------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 68        }
 69        public void FightOver3_2()
 70        {
 71            Console.WriteLine("{1}方法名:FightOver1------{0}", this._name, DateTime.Now);
 72            Console.WriteLine("{2}线程名:{0}------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 73            Console.WriteLine("{1}正在抢夺操作------{0}", this._name, DateTime.Now);
 74
 75            lock (this)
 76            {
 77                Console.WriteLine("{2}线程:{0} 在LowLevel1.FightOver2()中开始睡 1 秒------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 78                Thread.Sleep(1000);
 79            }
 80            Console.WriteLine("{2}线程名:{0} 已经离开操作------{1}", Thread.CurrentThread.Name, this._name, DateTime.Now);
 81        }
 82    }
 83    public class LowThreadDrive1
 84    {
 85        public void Drive1()
 86        {
 87            LowThread1 ll1 = new LowThread1("name1");
 88            LowThread1 ll2 = new LowThread1("name2");
 89
 90            Thread th1 = new Thread(ll1.FightOver1);
 91            Thread th2 = new Thread(ll2.FightOver2);
 92
 93            th1.Name = "线程1";
 94            th2.Name = "线程2";
 95
 96            th1.Start();
 97            th2.Start();
 98
 99        }
        public void Drive2()
        {
            LowThread1 ll1 = new LowThread1("ll1");
            LowThreadHelp1 llh = new LowThreadHelp1("llh");

            Thread th1 = new Thread(ll1.FightOver2);
            Thread th2 = new Thread(llh.FightHelp2);

            th1.Name = "线程1";
            th2.Name = "线程2";

            th1.Start();
            Thread.Sleep(1000);
            th2.Start();
        }
        public void Drive3()
        {
            LowThread1 ll1 = new LowThread1("ll1");
            LowThreadHelp1 llh = new LowThreadHelp1("llh");

            Thread th1 = new Thread(ll1.FightOver3_1);
            Thread th2 = new Thread(llh.FightHelp3);

            th1.Name = "线程1";
            th2.Name = "线程2";

            th1.Start();
            Thread.Sleep(500);
            th2.Start(ll1);
        }
        //注意 FightOver3和FightOver3_2()的不同之处在于lock块中，线程的sleep的时间前者5s后者1s
        //此处只是锁住了LowThread1的一个实例，并不是所有的实例。不同实例调用lock(this)并不相关。
        public void Drive4()
        {
            LowThread1 ll1 = new LowThread1("ll1");
            LowThread1 ll2 = new LowThread1("ll2");

            Thread th1 = new Thread(ll1.FightOver3_1);
            Thread th2 = new Thread(ll2.FightOver3_2);

            th1.Name = "线程1";
            th2.Name = "线程2";

            th1.Start();
            Thread.Sleep(500);
            th2.Start();
        }
    }
    internal class LowThreadHelp1
    {
        private string _name;

        public LowThreadHelp1(string name)
        {
            this._name = name;
            Console.WriteLine("{1}创建新的LowLevel1Help对象:{0}", name, DateTime.Now);
        }

        //这个方法对应的是LowLevel1.FightOver2()
        //当有线程调用LowLevel1.FightOver2()时,LowLevel1的Type对象被锁了,需要在Lock中睡5s
        //如果在5s内有线程调用这个FightHelp2()方法时,这个线程将被阻塞,进入线程列队
        //等到5s过后才能调用FightHelp2()中Lock里面的东西
        public void FightHelp2()
        {
            lock (typeof(LowThread1))
            {
                Console.WriteLine("{1}执行LowLevel1Help.FightHelp2():{0}", this._name, DateTime.Now);
            }
        }
        //这个方法对象的是LowLevel1.FightOver3()
        //当有线程执行LowLevel1.FightOver2()时,执行这个方法的对象被锁了,需要在Lock中睡5s
        //如果5s内有线程调用这个FightHelp3()方法时,这个线程将被阻塞,进入线程列队
        //等待5s过后才能调用FightHelp3()中Lock里的东西
        public void FightHelp3(object obj)
        {
            LowThread1 ll1 = (LowThread1)obj;
            lock (ll1)
            {
                Console.WriteLine("{1}执行LowLevel1Help.FightHelp3()------{0}", this._name, DateTime.Now);
                Console.WriteLine("{2}得到LowLevel1.Data:{0}------{1}", ll1.Data, this._name, DateTime.Now);
            }
        }
    }
}