/// <summary>
/// 公有静态构造方法作为构造函数。该函数会“偷偷”调用私有构造函数来创建对象，
/// 并将其保存在一个私有静态成员变量中。此后所有对于该函数的调用都将返回这一缓存对象。
/// </summary>
/// <returns></returns>
public static BaseSingleton GetInstance()
{
if (_instance == null)
{
// 注意：如果程序需要支持多线程，必须在此位置放置线程锁
_instance = new BaseSingleton();
}
return(_instance);
}
static void Main(string[] args)
{
#region 基础单例
BaseSingleton s1 = BaseSingleton.GetInstance();
BaseSingleton s2 = BaseSingleton.GetInstance();
if (s1 == s2)
{
Console.WriteLine("Singleton works, both variables contain the same instance.");
}
else
{
Console.WriteLine("Singleton failed, variables contain different instances.");
}
#endregion
#region 线程安全单锁单例
Console.WriteLine(
"{0}\n{1}\n\n{2}\n",
"If you see the same value, then singleton was reused (yay!)",
"If you see different values, then 2 singletons were created (booo!!)",
"RESULT:"
);
Thread process1 = new Thread(() =>
{
TestSingleton("FOO");
});
Thread process2 = new Thread(() =>
{
TestSingleton("BAR");
});
process1.Start();
process2.Start();
process1.Join();
process2.Join();
#endregion
#region 线程安全双锁单例
Console.WriteLine(DoubleLockSingleton.Instance.DoSomething("Hay"));
Console.WriteLine(DoubleLockSingleton.Instance.DoSomething("Halo"));
Console.ReadLine();
#endregion
}
