is @Singleton in dagger 2 thread safe?

Question

I'm trying to move everything in my app away from singletons, because I've been made aware that it's a bad programming practice, with that said, I'm looking into implementing Dagger 2 dependency injection. And I'm wondering, when you do @Singleton in Dagger 2 is that thread synchronized? if not how can I synchronize it, so I don't get any strange data anomalies from multiple threads touching the same things.

When I was creating singletons before I'd do something like this:

public class SomeSinglton {
    private static ClassName sInstance;

    private SomeSinglton () {
    }

    public static synchronized ClassName getInstance() {
        if (sInstance == null) {
            sInstance = new ClassName();
        }
        return sInstance;
    }

is the Dagger 2 @Singleton equivalent as far as being synchronized?

Answer 1

Yes, @Singletons in Dagger 2 are thread safe with double checked locking, same in Dagger 1. See ScopedProvider.