How to observeOn the calling thread in java rx?

Question

is there anyway to tell java rx to use the current thread in the observeOn function? I am writing code for the android syncadapter and I want the results be observed in the sync adapter thread and not in the main thread.

An example network call with Retrofit + RX Java looks something like that:

MyRetrofitApi.getInstance().getObjects()
.subscribeOn(Schedulers.io())
.observeOn(<current_thread>)
.subscribe(new Subscriber<Object>() {
    //do stuff on the sync adapter thread

}

I tried using using

...
.observeOn(AndroidSchedulers.handlerThread(new Handler(Looper.myLooper())))
...

which is the same way android rx creates the scheduler for the main thread but doesn't work anymore as soon as I substitute Looper.myLooper() for Looper.getMainLooper().

I could use the Schedulers.newThread() but as its complex syncing code with a lot of server calls I would be constantly creating a new thread just to fire new network calls that again create new threads to to launch more network calls. Is there a way to do this? Or is my approach itself completly wrong?

Answer 1

Try Using Schedulers.immediate()

MyRetrofitApi.getInstance().getObjects()
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.immediate())
.subscribe(new Subscriber<Object>() {
    //do stuff on the sync adapter thread

}

Its description says: Creates and returns a Scheduler that executes work immediately on the current thread.

NOTE:
I think it is okay to keep all the work on the SyncAdapter's thread because it is already using a different thread