【转】C#线程同步示例

using System;

using System.Threading;

//　银行帐户类

class Account

{       

         int balance;                         //　余额

         Random r = new Random();

         public Account(int initial)

         {

                   balance = initial;

         }

         // 取钱

         int Withdraw(int amount)

    {

                   if (balance < 0)

                   {

                            throw new Exception("余额为负！");

                   }

        lock (this)

                   {

                            if (balance >= amount)

                            {

                                     Console.WriteLine("原有余额:  " + balance);

                                     Console.WriteLine("支取金额: -" + amount);

                                     balance = balance - amount;

                                     Console.WriteLine("现有余额:  " + balance);

                                      return amount;

                            }

                            else

                            {

                                     return 0;           // 拒绝交易

                            }

                   }

         }

      // 测试交易

         public void DoTransactions()

         {

                   // 支取随机的金额100次

                   for (int i = 0; i < 100; i++)

                   {

                            Withdraw(r.Next(1, 100));

                   }

         }

}

class TestApp

{

         public static void Main()

         {

                   //　建立10个线程同时进行交易

                   Thread[] threads = new Thread[10];

                   Account acc = new Account (1000);//余额

                   for (int i = 0; i < 10; i++)

        {

                            Thread t = new Thread(new ThreadStart(acc.DoTransactions));

                            threads[i] = t;

                   }

                   for (int i = 0; i < 10; i++)

                   {

                            threads[i].Start();

                   }

         }

}