Thread safe services

Last month I explained how to tune Acceleo standalone engine threading. But services were still running in mutual exclusion because historically services didn't need to be thread safe. The result was a performance loss.
Services of a given service class couldn't run in parallel by default. It means threads will have to wait for other threads to run services. I noticed that a lot of service classes are thread safe, they don't use field or static references.

But as I can't decide if a service class is thread safe or not for you, I added an interface that bypass the mutual exclusion zone for a given service class. It allows multi threads to run services of a service class. This interface is IThreadSafeService. It declares nothing, so you just have to add the implements clause as following:

public MyServices implements IThreadSafeService {
...
}

But be aware, if you use this interface and your service class is not thread safe it can lead to random boggus behavior. And it can be difficult to find out what is the root cause of your troubles.