多线程的锁定
我做了一个小测试是关于多线程的,但是结果与我期望的不同。
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
namespace ThreadTest
{      
     public class LockCodeArea
     {
         private int count = 10;
         public void ReduceCount()
         {
             while (true)
             {
                 lock (this)  
                 {
                     Console.WriteLine("Current Count:{0}", count);
                     Console.WriteLine("Current thread HashCode is :{0}", Thread.CurrentThread.GetHashCode());
                     Thread.Sleep(100);
                     --count;
                     if (count > 0)
                         continue;
                     else
                         break;
                 }
             }
         }
     }
     class Program
     {
         static void Main(string[] args)
         {
             LockCodeArea testClass = new LockCodeArea();
             Thread firsThread = new Thread(new ThreadStart(testClass.ReduceCount));
             Thread secondThread = new Thread(new ThreadStart(testClass.ReduceCount));
             Console.WriteLine("Main HashCode is :{0}", Thread.CurrentThread.GetHashCode());
             Console.WriteLine("First thread Hashcode is :{0}",firsThread.GetHashCode());
             Console.WriteLine("Second thread HashCode is :{0}", secondThread.GetHashCode());
             firsThread.Start();
             secondThread.Start();
             if (!firsThread.IsAlive)
                 Thread.Sleep(1000);
             Console.WriteLine("Press Any Key to Continue!");
             Console.WriteLine("Main HashCode is :{0}", Thread.CurrentThread.GetHashCode());
             Console.ReadLine();
         }
     }
}
本来是希望使用Lock之后,只存在要么firstThread减数,要么secondThread减数,为什么会有firstThread和secondThead
交替减数的情况。我已经使用Lock锁定代码区了。???各位帮帮忙呀。
------解决方案--------------------注意,lock锁定的块同一时间只有一个线程能访问,你目前的代码锁定的是while内的代码。也就是说有2个线程都到达了循环内,一个现成continue的时候另一个线程乘机执行Console.WriteLine....
如果要同一时间只有1个线程能执行整个循环,就要把整个循环(10次)都锁住,也就是说:
C# code
 public void ReduceCount()
        {
            lock (this)
            {
                while (true)
                {
                    Console.WriteLine("Current Count:{0}", count);
                    Console.WriteLine("Current thread HashCode is :{0}", Thread.CurrentThread.GetHashCode());
                    Thread.Sleep(100);
                    --count;
                    if (count > 0)
                        continue;
                    else
                        break;
                }
            }
        }