Hi folks. I am confused with

withTimeout

. I have a function which can block the thread for undefined time. The caller should get timeout exception after timeout. The function doesn't support cancellation. There is a similar case, but it doesn't work as described. https://stackoverflow.com/questions/47635367/kotlin-coroutines-with-timeout/47641886#47641886 The snippet behind blocks for 10 seconds.

runBlocking {
   val work = async { Thread.sleep(10000) }
   withTimeout(100) {
        work.await()
   }
}

There are 3 solutions, which helps to make it working: - use

GlobalScope.async

- use

async(NonCancellable + <http://Dispatchers.IO|Dispatchers.IO>)

. Scope will await for async result if i don't specify

NonCancellable

.

<http://Dispatchers.IO|Dispatchers.IO>

is needed because

runBlocking

is single threaded. - use custom

scope

Am I missing something? Is there simpler approach?

withTimeout

is doing what you want. It's

runBlocking

that's getting in your way.

Yes, that's what I want. I understand that I'll abandon execution

Then

GlobalScope

is your solution.

I don't think that this solution will work

coroutineScope {
   val work = async { Thread.sleep(10000) }
   withTimeout(100) { work.await() }
}

Structured concurrency demands that a parent coroutine can only complete after it's children are complete. So any solution that can break structured concurrency will work for you. i.e

GlobalScope

, custom scope,

NonCancellable

.