onError not called for StackOverflowError?

[boris-petrov]

I'm not exactly sure on the semantics of onError (any of those - Single, Observable, etc) - it has a Throwable as an argument however I don't see it being called for StackOverflowError for example. Am I doing something wrong or is this by design? If this is by design, a few things:

1. Why is this not written in the documentation?
2. Why is onError passed a Throwable and not Exception?
3. How do I actually catch ANY exception as I need to do some cleanup in all cases (unlock locks e.g.)?

Thanks!

[akarnokd]

StackOverflowError is considered fatal and is propagated via rethrows as you can't recover from it anyway.

https://github.com/ReactiveX/RxJava/blob/2.x/src/main/java/io/reactivex/exceptions/Exceptions.java#L50

#748

[boris-petrov]

Thanks for the response. I've read some of the threads on the topic, it makes sense. Perhaps that should be documented somewhere though. And, still, I'm not sure how to handle my question number 3 - in "normal synchronous" Java I can do:

try {
    lockLocks();
} catch (Throwable t) {
    unlockLocks();
    throw t;
}

Which is "safe" in both senses - I unlock the locks and then I rethrow the lethal exception. How can I do the same in Rx?

P.S. Right now I do:

Action doFinally = () -> { unlockLocks() };
maybe.doOnDispose(doFinally).doOnEvent((_unused1, _unused2) -> doFinally.run())

But this doesn't work for StackOverflow...

[akarnokd]

Don't use locks and RxJava together.

[boris-petrov]

Not exactly the answer I was looking for but thanks nevertheless! :)