Java synchronizers - Countdownlatch

Package java.concurrency contains many high level APIs for working with concurrency. It has been added to JDK in version 5. It's quite long time ago. However many developers still use raw Thread and synchronization. I'm pretty sure it is not because they like it but more likely they don't know what kind of goodies they have at their disposal. So in order to spread the word I would like to present Java synchronizers and how to work with them.

Humility lesson

As software developers we are dealing with bugs everyday. Through the years we have created many techniques that help us avoid them. TDD, pair programming, code review etc. Unfortunately none of them are perfect. 

Comments ? No, thank you...

Dear Programmers ! Please, do not write comments in your code. Seriously. I mean it. In most cases comments are totally useless so what is the point in writing them ?