``` withTimeoutOrNull(1000) { suspendCancellab...

# coroutines

[irus]

withTimeoutOrNull(1000) {
    suspendCancellableCoroutine<Unit> { cont ->
        cont.invokeOnCancellation {
            cont.resumeWithException(CancellationException("Hello!")) // 1
            cont.resumeWithException(RuntimeException("Hello!")) // 2
        }
    }
}

Can't find place in documenation where difference between (1) and (2) described

[Alexandre]

Sonar won’t like the (2) 🐿️

[irus]

Because user shouldn't use RuntimeExceptions directly?

[irus]

Okay, found https://github.com/Kotlin/kotlinx.coroutines/blob/master/docs/exception-handling.md#cancellation-and-exceptions

[irus]

@elizarov Is it okay to resume with CancellationException during cancellation? I trying to cancel coroutine and underlying future, and future itself has cancellation handler. So in this handler I normally resume with`CancellationException` (for case when future cancelled by http client).

[elizarov]

You don’t need to resume a coroutine inside invokeOnCancellation. When invokedOnCancellation block is invoked, the suspended coroutine had been already resumed with CancellationException by coroutines machinery. invokeOnCancellation is there to notify you that this had happened, so that you can cancel some other work that had been performed.

[irus]

Yes, this is how things should work.

But in my case:

suspend fun HttpAsyncClient.execute(request: HttpUriRequest): HttpResponse {
    return suspendCancellableCoroutine { cont: CancellableContinuation<HttpResponse> ->
        val callback = object : FutureCallback<HttpResponse> {
            override fun completed(result: HttpResponse) {
                cont.resumeWith(Result.success(result))
            }

            override fun cancelled() {
                cont.resumeWith(Result.failure(FutureCallbackCanceledException(request)))
            }

            override fun failed(ex: Exception) {
                cont.resumeWith(Result.failure(ex))
            }
        }

        val future = this.execute(request, callback)

        cont.cancelFutureOnCancellation(future)
        Unit
    }
}

I have cancelled handler, and it's being called when invokeOnCancellation handler cancels future

[elizarov]

See this issue: https://github.com/Kotlin/kotlinx.coroutines/issues/830 It should give you some choices on what you can do.

[elizarov]

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