Since I was never really happy with the answers I received I had already given up and solved the concurrency issues with time but without having actual tests that proved that they were not existing any more. But today I stumbled upon a solution for the problem.
Links that explain writing those kind of tests:
- https://github.com/junit-team/junit/wiki/Multithreaded-code-and-concurrency
- http://tempusfugitlibrary.org/recipes/2012/05/20/testing-concurrent-code/
- http://www.planetgeek.ch/2009/08/25/how-to-find-a-concurrency-bug-with-java/
In short all these tests initialize Runnable and start them at exactly the same time to achieve a maximum concurrency-load, this way concurrency issues should be exposed.
