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I've just found an interesting article: <https://betterprogramming.pub/the-silent-killer-thats-crashing-your-coroutines-9171d1e8f79b>
What do the experts say about the proposed "double checked" cancellation?
Thanks.

Here's a thread: <https://github.com/Kotlin/kotlinx.coroutines/issues/3658|https://github.com/Kotlin/kotlinx.coroutines/issues/3658>

tl;dr: The experts improved slightly on my suggestion, and added it to the docs for `await()` :heart::bow:

I'm glad you found it interesting! If I was writing it again I think I'd probably tone down the drama :smile: it's a bit over the top

Could you explain the difference between
```try {
  // do anything
} catch (e: Throwable) {
  if (e is CancellationException) currentCoroutineContext().ensureActive()
  handleException(e)
}```
described in the <https://github.com/Kotlin/kotlinx.coroutines/issues/3658#issuecomment-1943562914|last comment> and the one currently in the kdoc:
```try {
   deferred.await()
} catch (e: CancellationException) {
   currentCoroutineContext().ensureActive() // throws if the current coroutine was cancelled
   processException(e) // if this line executes, the exception is the result of `await` itself
}```
Thanks.

Sure! The one in the kdoc actually uses `catch (e: CancellationException`, so it's similar to the one with `if (e is CancellationException)`. If you catch all throwables _and_ omit the `is` check, as I did in my article, cancellations will be able to take precedence over real errors. Narrowing the catch clause or including the `is` check are both ways to avoid that.

OMG, I somehow missed the different catched exception types of the two `catch` clauses.
I need a rest, reading through the above issue you linked and checking all related things has really drained my brain :smile:
(Just for reference, I edited my comment above to make it clear which two "variants" I have referred to...)

I ended up with the following (slightly different) implementation: <https://github.com/kotlinw/kotlinw/blob/05dde5f77d400bc51e49c19ec89bea25f8d7575a/kotlinw-util-coroutine-mp/src/commonMain/kotlin/kotlinw/util/coroutine/DeferredUtil.kt#L9-L37|https://github.com/kotlinw/kotlinw/blob/05dde5f77d400bc51e49c19ec89bea25f8d7575a/k[…]mp/src/commonMain/kotlin/kotlinw/util/coroutine/DeferredUtil.kt>
I hope it is correct based on the plethora of things I have learnt today :)
Thanks for your help.