RxKotlin (RxJava2) timeout() doesn't throw TimeoutException

Question

I'm trying to get an example working that uses two different timeout values. An initial larger value for the first emission and then shorter values for all subsequent emissions. The example is converted to Kotlin from Java for RxJava v1x, although I am attempting this is v2x (not sure if that makes any difference).

The problem is that the timeout for the first event doesn't throw a TimeoutException. With the value set below 500ms, I'm expecting a stack trace to be printed, but I get output as if no timeout has occurred (subsequent emissions with timeout set to 40ms results in stack trace as expected). What is wrong with the following example that prevents the initial timeout from succeeding?

fun nextSolarEclipse(after: LocalDate): Observable<LocalDate> {
    return Observable
            .just(
                    LocalDate.of(2016, Month.MARCH, 9),
                    LocalDate.of(2016, Month.SEPTEMBER, 1),
                    LocalDate.of(2017, Month.FEBRUARY, 26),
                    LocalDate.of(2017, Month.AUGUST, 21),
                    LocalDate.of(2018, Month.FEBRUARY, 15),
                    LocalDate.of(2018, Month.JULY, 13),
                    LocalDate.of(2018, Month.AUGUST, 11),
                    LocalDate.of(2019, Month.JANUARY, 6),
                    LocalDate.of(2019, Month.JULY, 2),
                    LocalDate.of(2019, Month.DECEMBER, 26)
            )
            .skipWhile { date ->
                !date.isAfter(after)
            }
            .zipWith(
                    Observable.interval(500, 50, TimeUnit.MILLISECONDS),
                    { date, _ -> date }
            )
}

fun main(args: Array<String>) {
    nextSolarEclipse(LocalDate.now())
            .timeout<Long, Long>(
                    { Observable.timer(400, TimeUnit.MILLISECONDS) },
                    { Observable.timer(40, TimeUnit.MILLISECONDS) }
            )
            .subscribe(
                    { println(it) },
                    { it.printStackTrace() },
                    { println("Completed") }
            )

    TimeUnit.MILLISECONDS.sleep(2000)
}

Edit: 20-Jun-17

With Kotlin 1.1.2-5, using IntelliJ, with the suggested alteration applied, I still get the error. Attempting to run the code anyway results, as I would expect, with:

Error:(34, 21) Kotlin: Interface Function does not have constructors

score 4 · Accepted Answer · answered Jun 19 '17 at 22:15

4

This is yet another case of Kotlin implying you need a function instead of a Observable instance. Try this:

.timeout<Long, Long>(
     Observable.timer(400, TimeUnit.MILLISECONDS),
     Function { Observable.timer(40, TimeUnit.MILLISECONDS) }
)

answered Jun 19 '17 at 22:15

akarnokd

69,132
14
157
192

If I do that, I get an interface Function does not have constructors, and I don't think I want to implement it as an anonymous object. – junglie85 Jun 20 '17 at 07:21
I'm not experienced with Kotlin and without that `Function` prefix the code won't compile for me. I'm guessing it's the notorious SAM issue. Perhaps you can write `{ it -> ... }` instead. – akarnokd Jun 20 '17 at 07:53
If I try it any other way other than as originally posted, I get the error `None of the following functions can be called with the arguments supplied`. The function I think I want is `@CheckReturnValue @SchedulerSupport public final fun timeout(firstTimeoutIndicator: ObservableSource!, itemTimeoutIndicator: Function!>!): Observable! defined in io.reactivex.Observable`, which is as you suggest in your initial comment, but with/without `Function` I still get the aforementioned errors. – junglie85 Jun 20 '17 at 08:40
The example I gave in the answer works for me with Kotlin 1.1.2. – akarnokd Jun 20 '17 at 09:59
1

You may have to manually `import io.reactivex.functions.Function`. – akarnokd Jun 20 '17 at 20:48
Well, I'll be damned! I'm pretty sure I use an IDE so as not to need to worry about things like that, which is why I don't use a text editor. Thanks @akarnokd. – junglie85 Jun 20 '17 at 21:07

RxKotlin (RxJava2) timeout() doesn't throw TimeoutException

1 Answers1