Name for this pattern? (Answer: lazy initialization with double-checked locking)

Question

Consider the following code:

public class Foo
{
    private static object _lock = new object();

    public void NameDoesNotMatter()
    {
        if( SomeDataDo         


        

Answer 1

The part that I'm especially interested in identifying as a pattern is the check -> lock -> check.

That is called double-checked locking.

Beware that in older Java versions (before Java 5) it is not safe because of how Java's memory model was defined. In Java 5 and newer changes were made to the specification of Java's memory model so that it is now safe.