singleton

DesignPatternGuru/DesignPatternGuru.sln

@@ -11,6 +11,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Builder", "Builder\Builder.
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Prototype", "Prototype\Prototype.csproj", "{3A8E007E-79D4-499B-8D19-BF745EC9C68E}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "CreationalPatterns", "CreationalPatterns", "{C470237E-3C3B-49E3-BA4C-86884EC28413}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Singleton", "Singleton\Singleton.csproj", "{79AC3F3A-CE95-40C4-94E6-31CC85494E41}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -33,10 +37,21 @@ Global
 		{3A8E007E-79D4-499B-8D19-BF745EC9C68E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{3A8E007E-79D4-499B-8D19-BF745EC9C68E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3A8E007E-79D4-499B-8D19-BF745EC9C68E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{79AC3F3A-CE95-40C4-94E6-31CC85494E41}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{79AC3F3A-CE95-40C4-94E6-31CC85494E41}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{79AC3F3A-CE95-40C4-94E6-31CC85494E41}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{79AC3F3A-CE95-40C4-94E6-31CC85494E41}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{4F58C486-7121-435B-B7B2-F3ADD0FBE2AE} = {C470237E-3C3B-49E3-BA4C-86884EC28413}
+		{8310590F-E10F-4845-8737-AF3CEF4583B1} = {C470237E-3C3B-49E3-BA4C-86884EC28413}
+		{FD2896D5-8199-4036-8D45-1CC0D3B4B79F} = {C470237E-3C3B-49E3-BA4C-86884EC28413}
+		{3A8E007E-79D4-499B-8D19-BF745EC9C68E} = {C470237E-3C3B-49E3-BA4C-86884EC28413}
+		{79AC3F3A-CE95-40C4-94E6-31CC85494E41} = {C470237E-3C3B-49E3-BA4C-86884EC28413}
+	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {3E5A9C6B-2E8A-466E-B5E0-4379902EFFAC}
 	EndGlobalSection

DesignPatternGuru/Singleton/BasicSingleton/Client.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton.BasicSingleton
+{
+	internal class Client
+	{
+		public static void DoTest()
+		{
+			Console.WriteLine("Basic Singleton");
+			Singleton s1 = Singleton.GetInstance();
+			Singleton s2 = Singleton.GetInstance();
+
+			if (s1 == s2)
+				Console.WriteLine("Both instances are same");
+			else
+				Console.WriteLine("Instances are different");
+		}
+	}
+}

DesignPatternGuru/Singleton/BasicSingleton/Singleton.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton.BasicSingleton
+{
+	internal class Singleton
+	{
+		private static Singleton _instance;
+
+		private Singleton()
+		{
+
+		}
+
+		public static Singleton GetInstance()
+		{
+			if (_instance == null)
+				_instance = new Singleton();
+
+			return _instance;
+		}
+	}
+}

DesignPatternGuru/Singleton/Program.cs

@@ -0,0 +1,14 @@
+namespace Singleton
+{
+	internal class Program
+	{
+		static void Main(string[] args)
+		{
+			BasicSingleton.Client.DoTest();
+
+			Console.WriteLine();
+
+			ThreadSageSingleton.Client.DoTest();
+		}
+	}
+}

DesignPatternGuru/Singleton/Singleton.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

DesignPatternGuru/Singleton/ThreadSageSingleton/Client.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton.ThreadSageSingleton
+{
+	internal class Client
+	{
+		public static void DoTest()
+		{
+			Console.WriteLine(
+				"Thread safe Singleton",
+				"If you see the same value, then both instances are same.",
+				"If you see differnt values, then 2 differnect instances are created.",
+				"RESULT: ");
+
+			Thread process1 = new Thread(() =>
+			{
+				TestSingleton("FOO");
+			});
+			Thread process2 = new Thread(() =>
+			{
+				TestSingleton("BAR");
+			});
+
+			process1.Start();
+			process2.Start();
+
+			process1.Join();
+			process2.Join();
+		}
+
+		public static void TestSingleton(string value)
+		{
+			Singleton singleton = Singleton.GetInstance(value);
+			Console.WriteLine(singleton.Value);
+		}
+	}
+}

DesignPatternGuru/Singleton/ThreadSageSingleton/Singleton.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Singleton.ThreadSageSingleton
+{
+	internal class Singleton
+	{
+		private static Singleton _instance;
+
+		private static readonly object _lock = new object();
+
+		public string Value { get; set; }
+
+		private Singleton()
+		{
+
+		}
+
+		public static Singleton GetInstance(string value)
+		{
+			if (_instance == null)
+			{
+				lock (_lock)
+				{
+					if (_instance == null)
+					{
+						_instance = new Singleton();
+						_instance.Value = value;
+					}
+				}
+			}
+
+			return _instance;
+		}
+	}
+}