switchIfEmpty - fix backpressure bug and lost requests #2996
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davidmoten
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| @@ -38,33 +38,35 @@ public OperatorSwitchIfEmpty(Observable<? extends T> alternate) { | |||
| final SwitchIfEmptySubscriber parent = new SwitchIfEmptySubscriber(child, ssub); | |||
| ssub.set(parent); | |||
| child.add(ssub); | |||
| child.setProducer(new Producer() { | |||
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I'd instantiate the ProducerArbiter before parent and supply it to SwitchIfEmptySubscriber and child, saving on this 'relaying' allocation. (Remark, our life would be much easier if we could implement Producer in Subscriber, but since request() is protected final, it is unoverridable :( )
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Yeah life would be easier if request() was public. I wouldn't mind seeing it opened up, do you think it worth discussing in an issue?
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It's too late for that. We will be careful in RxJava 2.0.
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Made those changes, ta. |
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Cleaned up a bit, made the parent subscriber class a static class and improved names |
| child.onNext(t); | ||
| } | ||
| })); | ||
| ssub.set(alternate.unsafeSubscribe(new AlternateSubscriber<T>(child, arbiter))); |
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Instead:
AlternateSubscriber<T> as = new AlternateSubscriber<T>(child, arbiter);
ssub.set(as);
alternate.unsafeSubscribe(as);
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Well spotted, thanks. Updated. |
| @Override | ||
| public void onNext(T t) { | ||
| child.onNext(t); | ||
| arbiter.produced(1); |
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I think this produced(1) is unnecessary: sure the arbiter's value will grow indefinitely, but there won't be any further setProducer on it thus conserving the requested/delivered amount is less important.
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The hey-you-delivered-more-than-requested check is useful though
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In that case, you need to add this to the other child.onNext() call as well.
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Erk, thanks for noticing that. Updated. |
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Great, thanks! |
switchIfEmpty - fix backpressure bug and lost requests
OperatorSwitchIfEmptysuffered from these conditions:setProducercalledsuper.setProducerinstead ofchild.setProducerBot the of the above problems are solved by using
ProducerArbiterfrom @akarnokd.Included two unit tests that failed on previous code.