Design patterns Singleton Singleton (C#)
Example
Singletons are used to ensure that only one instance of an object is being created. The singleton allows only a single instance of itself to be created which means it controls its creation. The singleton is one of the Gang of Four design patterns and is a creational pattern.
Thread-Safe Singleton Pattern
public sealed class Singleton
{
private static Singleton _instance;
private static object _lock = new object();
private Singleton()
{
}
public static Singleton GetSingleton()
{
if (_instance == null)
{
CreateSingleton();
}
return _instance;
}
private static void CreateSingleton()
{
lock (_lock )
{
if (_instance == null)
{
_instance = new Singleton();
}
}
}
}
Jon Skeet provides the following implementation for a lazy, thread-safe singleton:
public sealed class Singleton
{
private static readonly Lazy<Singleton> lazy =
new Lazy<Singleton>(() => new Singleton());
public static Singleton Instance { get { return lazy.Value; } }
private Singleton()
{
}
}
