Terminate Observable by timeout

Question

I'm trying to limit life of observable by timeout:

def doLongOperation() = {
   Thread.sleep(duration)
   "OK"
}

def firstStep = Observable.create(
  (observer: Observer[String]) => {
    observer.onNext(doLongOperation())
    observer.onCompleted()
    Subscription()
  }
)

firstStep
  .timeout(1 second)
  .subscribe(
    item => println(item),
    throwable => throw throwable,
    () => println("complete")
  )

I would like to distinguish between following results:

Observable finished by timeout, no result obtained
Exception thrown during execution
Execution finished successfully, return value

I can process cases 2 and 3 with no problem in partials onNext and onError, but how do I detect if observable finished by timeout?

One more thing: I've never get into block onComplete, though there is a call to obeserver.onCompleted() in my code. Why?

Operator `timeout` will emit a TimeoutException on the onError lane. — akarnokd, Nov 12 '15 at 15:27
@akarnokd, What's wrong with my code then? Since I don't get any exception — Nyavro, Nov 12 '15 at 15:48

score 1 · Accepted Answer · answered Nov 12 '15 at 16:04

1

If a timeout happens, that TimeoutException is emitted on the computation thread where a throw throwable is ends up being ignored and your main thread won't and can't see it. You can add toBlocking after the timeout so any exception will end up on the same thread:

firstStep
  .timeout(1 second)
  .toBlocking()
  .subscribe(
    item => println(item),
    throwable => println(throwable),
    () => println("complete")

)

answered Nov 12 '15 at 16:04

akarnokd

69,132
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You are absolutely right, exception get thrown. The problem was in another place: I was using wrong dependencies: "com.netflix.rxjava" instead of "io.reactivex". – Nyavro Nov 12 '15 at 16:15

score 0 · Answer 2 · answered Nov 12 '15 at 16:18

0

TimeoutException gets thrown indeed. The problem was caused by using wrong libraries. I had "com.netflix.rxjava" in my dependencies, instead of "io.reactivex"

answered Nov 12 '15 at 16:18

Nyavro

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Terminate Observable by timeout

2 Answers2