Design Patterns-thread-safe Singleton mode (C #)

1, a Hungry man type single case mode

A hungry man singleton mode-by Chimomonamespace csharplearning{public    sealed class Singleton    {        private static readonly Sing Leton instance = new Singleton ();        Private Singleton () {} public        static Singleton Instance        {            get {return Instance;}        }    }

2, lazy single-case mode

2.1, the use of internal class

Lazy Singleton mode: With an internal class-by Chimomonamespace csharplearning{public    sealed class Singleton    {        private Singleton () { }        private Static class Singletonholder        {public            static readonly Singleton instance = new Singleton ();        } Public        static Singleton Instance        {            get {return singletonholder.instance;}}}    

2.2, Ordinary Lock

Lazy single-case mode: normal lock-by chimomonamespace csharplearning{public    sealed class Singleton    {        private static volatile Singleton instance;        private static readonly Object syncRoot = new Object ();        Private Singleton () {} public        static Singleton Instance        {            get            {                lock (syncRoot)                {                    if ( instance = = null)                    {                        instance = new Singleton ();}                }                return instance;}}}    

2.3. Double Detection plus lock

Lazy single-case mode: Dual detection lock-by chimomonamespace csharplearning{public    sealed class Singleton    {        private static volatile Singleton instance;        private static readonly Object syncRoot = new Object ();        Private Singleton () {} public        static Singleton Instance        {            get            {                if (Instance = = null)                {                    Lock (SyncRoot)                    {                        if (instance = = null)                        {                            instance = new Singleton ();                }}} return instance;}}}    

Design Patterns-thread-safe Singleton mode (C #)