Someone apparently disliked this comment, but check out http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html http://www.cs.umd.edu/~pugh/java

Someone apparently disliked this comment, but check out http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLo.... Scroll down to "Fixing Double-Checked Locking using Volatile." It's five lines of code without braces, and can be applied without any creativity or reasoning.