Learning RxJava - Second Edition

Single

When you want to run tasks sequentially on a single thread, you can use Schedulers.single() to create a Scheduler. This is backed by a single-threaded implementation appropriate for event looping. It can also be helpful to isolate fragile, non-thread-safe operations to a single thread. The following is an example of the Schedulers.single() factory method usage:

Observable.just("Alpha", "Beta", "Gamma", "Delta", "Epsilon")          .subscribeOn(Schedulers.single());