.net中的死锁示例？

Question

任何人都可以在c#中提供一个简单的死锁示例代码吗？请告诉您在C#代码示例中找到死锁的最简单方法.(可能是在给定的示例代码中检测死锁的工具.)

注意:我有VS 2008

Answer 1

一种常见的方法是,如果您具有未按相同顺序获取的嵌套锁.线程1可以获取锁A,线程2可以获取锁B,它们会死锁.

var a = new object();
var b = new object();

lock(a) {
   lock(b) {

   }
}

// other thread
lock (b) { 
  lock(a) {

  }
}

编辑:非锁定示例..使用等待句柄.假设苏格拉底和笛卡尔都有牛排,他们都是有礼貌的哲学家,为了吃东西需要叉子和刀子.然而,他们只有一套银器,所以每个人都可以抓住一个器具,然后永远等待对方交出他们的器具.

参见餐饮哲学家的问题

WaitHandle fork = new AutoResetEvent(), knife = new AutoResetEvent();

while(Socrates.IsHungry) {
   fork.WaitOne();
   knife.WaitOne();
   Eat();
   fork.Set();
   knife.Set();
} 

// other thread
while(Descartes.IsHungry) {
   knife.WaitOne();
   fork.WaitOne();
   Eat();
   knife.Set();
   fork.Set();
} 

Answer 2

这是在C#代码中创建死锁的典型代码.查看此MSDN文章:http://msdn.microsoft.com/en-us/magazine/cc188793.aspx

using System;

using System.Threading;


public class Simple {

    static object A = new object();

    static object B = new object();


    static void MethodA()
    {
        Console.WriteLine("Inside methodA");
        lock (A)
        {
            Console.WriteLine("MethodA: Inside LockA and Trying to enter LockB");
            Thread.Sleep(5000);           
            lock (B)
            {
                Console.WriteLine("MethodA: inside LockA and inside LockB");
                Thread.Sleep(5000);
            }
            Console.WriteLine("MethodA: inside LockA and outside LockB");
        }
        Console.WriteLine("MethodA: outside LockA and outside LockB");
    }

    static void MethodB()
    {
        Console.WriteLine("Inside methodB");
        lock (B)
        {
            Console.WriteLine("methodB: Inside LockB");
            Thread.Sleep(5000);
            lock (A)
            {
                Console.WriteLine("methodB: inside LockB and inside LockA");
                Thread.Sleep(5000);
            }
            Console.WriteLine("methodB: inside LockB and outside LockA");
        }
        Console.WriteLine("methodB: outside LockB and outside LockA");
    }

    public static void Main(String[] args)
    {

        Thread Thread1 = new Thread(MethodA);
        Thread Thread2 = new Thread(MethodB);
        Thread1.Start();
        Thread2.Start();
        Console.WriteLine("enter.....");
        Console.ReadLine();

    }
}