[Question `AsyncThrowingSequence`] Should failure resume and fail all producers/consumers

[twittemb]

Hi,

We’ve recently merged a PR #152 where the finish operation instantly resumes all the pending producers and consumers (with a nil value), thus ending all the iterators.

I was wondering if we should have the same behaviour for failures. As it is a terminal event, we have the same kind of risk for infinite suspensions. I guess when sending a failure, all the pending operations should resume instantly. All the awaiting consumers should receive the failure and the future iterations should also resume instantly.

@phausler what do you think ?

The fail(_:) function would also be not async. It makes sense since, as a terminal event, no back pressure should be applied.

[phausler]

the logic here is sound. The behavior we would ideally want for multiple consumers is that if a fail is sent, it needs to definitely be consumed; that is a long way of saying - I need to ruminate on this one a bit.

[phausler]

so after thinking about the situations for this: provided it can be accomplished w/o starving either side (which I think I have convinced myself that is accomplishable as you outlined). From a symmetry standpoint it feels right to have back pressure be the same for finish and fail. In short that sounds like a good change to make.

[twittemb]

Thanks for your analysis. I’ll work on that as soon as I can. I will keep the issue open until the PR is done so we can make the link between the issue and the PR.

[twittemb]

#164