Observable interval scheduling on Schedulers.trampoline cause a infinite loop

[sopping]

This code cause a infinite loop when snippt-1 interval complete.

        System.out.println("start");
        // snippt-1
        Observable.interval(1, TimeUnit.SECONDS, Schedulers.trampoline()).take(10)
                .subscribe(aLong -> System.out.println(aLong + "; " + Thread.currentThread().getName()), Throwable::printStackTrace,
                        () -> System.out.println("complete1."));
        // snippt-2
        Observable.interval(1, TimeUnit.SECONDS, Schedulers.trampoline()).take(10)
                .subscribe(aLong -> System.out.println(aLong + "; " + Thread.currentThread().getName()), Throwable::printStackTrace,
                        () -> System.out.println("complete2."));

        Thread.sleep(30000);
        System.out.println("end");

This code will be fine

        System.out.println("start");

        Observable.interval(1, TimeUnit.SECONDS).take(10).subscribeOn(Schedulers.trampoline())
                .subscribe(aLong -> System.out.println(aLong + "; " + Thread.currentThread().getName()), Throwable::printStackTrace,
                        () -> System.out.println("complete1."));

        Observable.interval(1, TimeUnit.SECONDS).take(10).subscribeOn(Schedulers.trampoline())
                .subscribe(aLong -> System.out.println(aLong + "; " + Thread.currentThread().getName()), Throwable::printStackTrace,
                        () -> System.out.println("complete2."));

        Thread.sleep(30000);
        System.out.println("end");

Is something wrong with me?

[akarnokd]

It is the effect of sleeping-blocking nature of the trampoline scheduler that when it enters a synchronous periodic loop, the parent stream simply won't get the control to cancel that loop.

The second set of cases work because using subscribeOn has no effect (and runs on the main thread anyway) as the interval itself executes on the computation thread afterwards.

[sopping]

The tampoline works when I use 1.x.
I want to execute some interval sequentially on current thread. Can I?

[akarnokd]

The tampoline works when I use 1.x.

API changes and scheduler use has changed that exposes this issue.

I want to execute some interval sequentially on current thread. Can I?

That is Thread.sleep() in a loop. Why do you want this?

I've posted a fix for this type of cases in #5367.

[sopping]

Is there some replaceable way to do the same thing now?
This code seems ok:

Observable.range(1, interval).subscribeOn(Schedulers.trampoline()).map(aLong -> {
            TimeUnit.SECONDS.sleep(1);
            return aLong;
        }).subscribe(aLong -> System.out.println(aLong + "; " + Thread.currentThread().getName()));

[akarnokd]

You don't try to stop that setup, plus the sleep is so small I guess the whole thing completes pretty quickly anyway.

Closing via #5367.