在处理.net线程同步问题,有许多办法,这里所将谈到的是特定代码区的同步.
这些特定的代码区是方法中重要的代码段,他们可以改变对象的状态,或者更新另一个资源.
Monitor类用于同步代码去,其方式是使用Monitor.Enter()方法获得一个锁,然后使用Monitor.Exit()方法释放该锁.
示例如下:
using System;
using System.Threading;
namespace EnterExit
{
public class EnterExit
{
private int result=0;
public EnterExit()
{
}
public void NonCriticalSection()
{
Console.WriteLine("Enter Threah"+Thread.CurrentThread.GetHashCode());
for(int i=1;i<=5;i++)
{
Console.WriteLine("Result="+result++ +" ThreadID"+Thread.CurrentThread.GetHashCode());
Thread.Sleep(1000);
}
Console.WriteLine("Exiting Threah"+Thread.CurrentThread.GetHashCode());
}
public void CriticalSection()
{
Monitor.Enter(this);
Console.WriteLine("Enter Threah"+Thread.CurrentThread.GetHashCode());
for(int i=1;i<=5;i++)
{
Console.WriteLine("Result="+result++ +" ThreadID"+Thread.CurrentThread.GetHashCode());
Thread.Sleep(1000);
}
Console.WriteLine("Exiting Threah"+Thread.CurrentThread.GetHashCode());
Monitor.Exit(this);
}
public static void Main(String[] args)
{
EnterExit e=new EnterExit();
if(args.Length>0)
{
Thread nt1=new Thread(new ThreadStart(e.NonCriticalSection));
nt1.Start();
Thread nt2=new Thread(new ThreadStart(e.NonCriticalSection));
nt2.Start();
}
else
{
Thread ct1=new Thread(new ThreadStart(e.CriticalSection));
ct1.Start();
Thread ct2=new Thread(new ThreadStart(e.CriticalSection));
ct2.Start();
}
}
}
}
运行结果:
Enter Threah 1
Result=0 Thread1
Result=1 Thread1
Result=2 Thread1
Result=3 Thread1
Result=4 Thread1
Exiting Thread1
Enter Threah 2
Result=5 Thread2
Result=6 Thread2
Result=7 Thread2
Result=8 Thread2
Result=9 Thread2
Exiting Thread2
