static void Main(string[] args)
{
for (int i = 0; i < 100; i++)
{
LazySingleton s = LazySingleton.Instance;
s.PrintName();
}
}
public LazySingleton GetInstance()
{
if (Instance == null)
{
Instance = new LazySingleton();
}
return(Instance);
}
public static LazySingleton GetInstance()
{
if (s == null)
{
s = new LazySingleton();
}
return(s);
}
public static LazySingleton getInstance()
{
if (instanceSingleton == null)
{
instanceSingleton = new LazySingleton();
}
return(instanceSingleton);
}
public static LazySingleton getInstance()
{
// 每个线程来之前先等待锁
lock (syncObject)
{
if (instance == null)
{
instance = new LazySingleton();
}
}
return(instance);
}
static void Main(string[] args)
{
//Singleton s1 = Singleton.GetInstance();
//Singleton s2 = Singleton.GetInstance();
//Console.WriteLine(s1 == s2);
Singleton.Test();
//Console.WriteLine(Singleton.VERSION);
//LazySingleton ls1 = LazySingleton.GetInstance();
//LazySingleton ls2 = LazySingleton.GetInstance();
LazySingleton.Test();
}
static void Main(string[] args)
{
LazySingleton ls1 = LazySingleton.GetInstance();
ls1.Show();
LazySingleton ls2 = LazySingleton.GetInstance();
ls2.Show();
LazySingleton ls3 = LazySingleton.GetInstance();
ls3.Show();
Console.ReadLine();
}
static void Main(string[] args)
{
Console.WriteLine("************************************");
Console.WriteLine("Eager EagerSingleton Test");
Console.WriteLine("************************************");
//These Should Pass
EagerSingleton eagerSingleton1 = EagerSingleton.Instance;
EagerSingleton eagerSingleton2 = EagerSingleton.Instance;
Console.WriteLine("Is eager1==eager2: " + (eagerSingleton1 == eagerSingleton2));
Console.WriteLine("Extra test for fun: " + Object.ReferenceEquals(eagerSingleton1, eagerSingleton2));
Console.WriteLine();
Console.WriteLine("************************************");
Console.WriteLine("Lazy EagerSingleton Test");
Console.WriteLine("************************************");
//These Should Pass
LazySingleton lazySingleton1 = LazySingleton.Instance;
LazySingleton lazySingleton2 = LazySingleton.Instance;
Console.WriteLine("Is lazy1==lazy2: " + (lazySingleton1 == lazySingleton2));
Console.WriteLine("Extra test for fun: " + Object.ReferenceEquals(lazySingleton1, lazySingleton2));
Console.WriteLine();
Console.WriteLine();
Console.WriteLine("************************************");
Console.WriteLine("Generic Lazy Loading EagerSingleton Test");
Console.WriteLine("************************************");
//These Should Pass
Test1 test1A = Singleton <Test1> .Instance;
Test1 test1B = Singleton <Test1> .Instance;
Console.WriteLine("Is t1A==t1B: " + (test1A == test1B));
Console.WriteLine("Extra test for fun: " + Object.ReferenceEquals(test1A, test1B));
Console.WriteLine();
//These should Fail
Test2 test2A = Singleton <Test2> .Instance;
Test2 test2B = new Test2();
Console.WriteLine("Is t2A==t2B: " + (test2A == test2B));
Console.WriteLine("Extra test for fun: " + Object.ReferenceEquals(test2A, test2B));
Console.WriteLine();
Console.ReadKey();
}
public LazySingleton GetInstance()
{
if (singleton == null)
{
//唯一线程访问
lock (_lock)
{
if (singleton == null)
{
return(singleton = new LazySingleton());
}
}
}
return(singleton);
}
public static void Test()
{
Console.WriteLine($"Name: {LazySingleton.GetInstance().Name}");
}
static void Main()
{
/*
* Structural
*/
// constructors are protected, cannot use "new"
StructuralSingleton structuralSingletonOne = StructuralSingleton.Instance();
StructuralSingleton structuralSingletonTwo = StructuralSingleton.Instance();
// test for instance equality
if (structuralSingletonOne == structuralSingletonTwo)
{
Console.WriteLine("Objects are same instance");
}
/*
* Real-World
*/
RealWorldSingletonLoadBalancer balancerOne = RealWorldSingletonLoadBalancer.GetLoadBalancer();
RealWorldSingletonLoadBalancer balancerTwo = RealWorldSingletonLoadBalancer.GetLoadBalancer();
RealWorldSingletonLoadBalancer balancerThree = RealWorldSingletonLoadBalancer.GetLoadBalancer();
RealWorldSingletonLoadBalancer balancerFour = RealWorldSingletonLoadBalancer.GetLoadBalancer();
// test for equality
if (balancerOne == balancerTwo && balancerTwo == balancerThree && balancerThree == balancerFour)
{
Console.WriteLine("Same instance");
}
// load balance 15 server requests
RealWorldSingletonLoadBalancer loadBalancer = RealWorldSingletonLoadBalancer.GetLoadBalancer();
for (int i = 0; i < 15; i++)
{
string server = loadBalancer.Server;
Console.WriteLine("Dispatch request to: " + server);
}
/*
* .NET Optimized
*/
DotNetOptimizedSingleton dotNetBalancerOne = DotNetOptimizedSingleton.GetLoadBalancer();
DotNetOptimizedSingleton dotNetBalancerTwo = DotNetOptimizedSingleton.GetLoadBalancer();
DotNetOptimizedSingleton dotNetBalancerThree = DotNetOptimizedSingleton.GetLoadBalancer();
DotNetOptimizedSingleton dotNetBalancerFour = DotNetOptimizedSingleton.GetLoadBalancer();
// test for equality
if (dotNetBalancerOne == dotNetBalancerTwo && dotNetBalancerTwo ==
dotNetBalancerThree && dotNetBalancerThree == dotNetBalancerFour)
{
Console.WriteLine("Same instance");
}
// load balance 15 server requests
DotNetOptimizedSingleton dotNetBalancer = DotNetOptimizedSingleton.GetLoadBalancer();
for (int i = 0; i < 15; i++)
{
string server = dotNetBalancer.NextServer.Name;
Console.WriteLine("Dispatch request to: " + server);
}
/*
* Lazy
*/
LazySingleton lazySingletonOne = LazySingleton.Instance;
LazySingleton lazySingletonTwo = LazySingleton.Instance;
if (lazySingletonOne == lazySingletonTwo)
{
Console.WriteLine("Lazy Singletons are equal");
}
Console.WriteLine(lazySingletonOne.CheckCreation());
}
private static void PrintStudentdetails()
{
LazySingleton fromStudent = LazySingleton.GetInstance;
fromStudent.PrintDetails("From Student");
}
private static void PrintTeacherDetails()
{
LazySingleton fromTeacher = LazySingleton.GetInstance;
fromTeacher.PrintDetails("From Teacher");
}
static Nested()
{
instance = new LazySingleton();
}
