I need some help understanding how coroutines clea...

# coroutines

[Colin]

I need some help understanding how coroutines clean up after being cancelled. I have an example :-

I have a function that returns a ReceiveChannel, and inside that function I am starting new suspended functions.
Pseudocode:

suspend fun produceStrings(): ReceiveChannel<String> {
        return produce {
            send(suspendedFunction1())
            send(suspendedFunction2())
            send(suspendedFunction3())
        }
    }

The code that calls produceStrings is consuming the channel via consumeEach. If at some point I cancel the channel, I am expecting that the suspended functions inside the produce block are stopped. i.e. I have a breakpoint in suspendedFunction3() and I can see that the breakpoint is hit after I have cancelled the channel. Is this expected behaviour?

[Colin]

Having read some more, It might be because I was using Thread.sleep to slow down the function and thus that made the coroutine uncancellable

[marstran]

Cancellation is cooperative. The coroutine can only be cancelled at a suspension point.

[marstran]

The delay function is the suspending version of Thread.sleep.