```class ProduceStateScopeImpl<T>( state: MutableState<T>, override val coroutin...

# compose

[carbaj0]

class ProduceStateScopeImpl<T>(
    state: MutableState<T>,
    override val coroutineContext: CoroutineContext
) : ProduceStateScope<T>, MutableState<T> by state {

    override suspend fun awaitDispose(onDispose: () -> Unit): Nothing {
        try {
            suspendCancellableCoroutine<Nothing> { }
        } finally {
            onDispose()
        }
    }
}

Why suspendCancellableCoroutine<Nothing> { } is being executed?

[Zach Klippenstein (he/him) [MOD]]

Presumably because something is calling awaitDispose?

[Zach Klippenstein (he/him) [MOD]]

Also this question has nothing to do with compose, did you mean to post in #coroutines ?

[Adam Powell]

It's a class from compose-runtime 🙂

[Adam Powell]

It's the same basic pattern from `channelFlow`'s awaitClose

[carbaj0]

Thanks both for the answers

[carbaj0]

I will try to find out more about this, because it isn't clear to me

[Zach Klippenstein (he/him) [MOD]]

Can you elaborate on your question a bit? Why would you expect suspendCancellableCoroutine not to be executed?

[carbaj0]

when i saw the empty block i thought that nothing occurs

[carbaj0]

but of course the cancellation occurs anyway

[carbaj0]

public suspend inline fun <T> suspendCancellableCoroutine(
    crossinline block: (CancellableContinuation<T>) -> Unit
): T =
    suspendCoroutineUninterceptedOrReturn { uCont ->
        val cancellable = CancellableContinuationImpl(uCont.intercepted(), resumeMode = MODE_CANCELLABLE)
        /*
         * For non-atomic cancellation we setup parent-child relationship immediately
         * in case when `block` blocks the current thread (e.g. Rx2 with trampoline scheduler), but
         * properly supports cancellation.
         */
        cancellable.initCancellability()
        block(cancellable)
        cancellable.getResult()
    }

[carbaj0]

I was expecting a coroutineContext.cancel () or something like that 😅

[Adam Powell]

Ah, yeah that happens when the underlying LaunchedEffect restarts for a new key or leaves the composition 🙂

[carbaj0]

there are a new function in the kotlinx.coroutines a little more idiomatic, awaitCancellation()

[carbaj0]

/**
 * Suspends until cancellation, in which case it will throw a [CancellationException].
 *
 * This function returns [Nothing], so it can be used in any coroutine,
 * regardless of the required return type.
 */
public suspend fun awaitCancellation(): Nothing = suspendCancellableCoroutine {}

[carbaj0]

is the same implementation, no surprises 😆

[Adam Powell]

Yep, we added the awaitDispose scoped method before awaitCancellation came in 🙂