Another coroutine misunderstanding for me. I don't understand ; why `In 'uncaughtExceptionHandler' ...

# coroutines

[ylemoigne]

Another coroutine misunderstanding for me. I don't understand ; why In 'uncaughtExceptionHandler' ... is called ?

Untitled

[ylemoigne]

I found this https://github.com/Kotlin/kotlinx.coroutines/issues/871

[ylemoigne]

Then, how to prevent exception to be treated as unhandled ?

[Evan R.]

This is a guess, but check the last sentence on the documentation for close() (https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.channels/-send-channel/close.html):

Attempts to send or receive on a failed channel throw the specified cause exception.

It appears that your produce<String>() block will just move on to the next iteration after the close() and attempt to send, re-throwing the exception you closed the channel with. Because there’s no try/catch in the producer it’s being passed up to the CEH

[Evan R.]

I think adding a break in your if statement in the producer will fix the issue

[ylemoigne]

Indeed. Thanks. (I still hope for better documentation as produce doc says

Uncaught exceptions in this coroutine close the channel with this exception as a cause and
 * the resulting channel becomes _failed_, so that any attempt to receive from such a channel throws exception.

which I understood as throw Something() in produce block is equivalent to calling close(Something()) but the behavior are different

[Evan R.]

You might also test whether or not the following will hit the CEH:

Untitled

[Evan R.]

I imagine the exception may have hit the CEH because the produce scope threw a second exception after the channel was already closed

[ylemoigne]

With your example of doJob2, it hit CEH