Is it really correct that this code:

withContext(Dispatchers.Unconfined) {
   println(1)
   withContext(Dispatchers.Unconfined) { // Nested unconfined
       println(2)
   }
   println(3)
}

can really print

1, 3, 2

? If the inner

withContext

was a

launch

I'm fully on board with the fact that the order is undefined. But since

withContext

actually returns something it would mean that this code:

withContext(Dispatchers.Unconfined) {
   val result = withContext(Dispatchers.Unconfined) { 1 + 1 }
   println(result)
}

Could be broken?

What makes you say that it could print

1, 3, 2

? Have you seen that claim made somewhere? Since there are no calls to

launch

or

async

, I think your reasoning is correct and this code should execute sequentially.

From the kdoc for `Dispatchers.Unconfined`:

For example, the following code:
withContext(Dispatchers.Unconfined) {
   println(1)
   withContext(Dispatchers.Unconfined) { // Nested unconfined
       println(2)
   }
   println(3)
}
println("Done")

Can print both "1 2 3" and "1 3 2", this is an implementation detail that can be changed. But it is guaranteed that "Done" will be printed only when both withContext are completed.

Huh. I agree with you, that documentation does not match my understanding of how

withContext

works.

I'm feeling fairly sure that they meant to use

launch

in their example

Yeah, that been wrong for years now. https://youtrack.jetbrains.com/issue/KT-47032/Incorrect-code-example-for-Dispatchers.Unconfined-in-kotlinx.coroutines-docs

My PR that fixes this just landed

😬 just a bit later on it still refers to “both

withContext

calls” though.

Damn, I missed that. Will fix