Assuming I'm not using globals Scopes or supervisor scopes, is there any difference between launch a...

# coroutines

[Jacob]

Assuming I'm not using globals Scopes or supervisor scopes, is there any difference between launch and an async that returns a deferred<unit>?

[kevin.cianfarini]

launch returns a job, not a deferred.

[kevin.cianfarini]

I suppose Deferred is a job, though, so 🤷

[Casey Brooks]

I think the errors within the async coroutine are thrown at the point where deferred.await() is called, rather than the async { } function call itself.

[Jacob]

Doesn't structured concurrency make the errors from the async cancel the parent without calling await?

[Casey Brooks]

The result of the deferred is available when it is completed and can be retrieved by await method, which throws an exception if the deferred had failed.

It should still cancel the parent, but the exception thrown from the coroutine should be captured within the deferred and only thrown through deferred.await(). This is in contrast to launch which directly sends the captured exception to the CoroutineExceptionHandler

[Jacob]

in this example from the docs https://pl.kotl.in/_apz1GtoX two cancels everything without ever actually being awaited on https://kotlinlang.org/docs/composing-suspending-functions.html#structured-concurrency-with-async

[Jacob]

My suspicion here is that launch and async used to be a lot more distinguishable before structured concurrency was introduced, but now the differences are only notable if you somehow escape structured concurrency (not counting the difference in the return type)

[Patrick Steiger]

I feel like there’s no difference between async and launch w.r.t parent cancellation

Only difference is async returns a value on .await() and that value can actually be a thrown exception if it completed exceptionally