Write a standard lock() plus “double check” to create a critical section around a variable access.

Purpose:

• Any seasoned developer that has written multi threaded code would be familiar with this pattern. If the developer can tie it to both deadlock and performance reasons then it is a really good indicator.

Potential Answer:

public class SingletonObject         {             private static volatile Singleton _instance;             private static object lockObject = new object();             public static Singleton Instance             {                 get                 {                     if (instance == null)                     {                         lock (lockObject)                         {                             if (instance == null)                                 instance = new Singleton();                         }                     }                     return instance;                 }             }         }