The Singleton Pattern - Anti-Pattern or Solution?

Singleton is indeed a rather infamous pattern: There are many voices out there that describe Singleton as a general problem in code, as an anti-pattern, as dangerous, or even as evil. Still, despite the bad reputation and the many negative aspects, if used judiciously and if implemented properly, Singleton has proven to be a useful solution for representing the few global aspects in your code.

This talk tries to give a balanced overview of the Singleton pattern. I will show the cons as well as the pros and will demonstrate how to properly deal with Singletons to overcome the major disadvantages. In particular, I will show how to implement Singletons such that dependencies to implementation details are avoided, code can be easily changed and full testability is given.