Hi folks, I was wondering if there is a way to cancel/stop `runBlocking`(which has an associated con...

# coroutines

[winchester044]

Hi folks, I was wondering if there is a way to cancel/stop `runBlocking`(which has an associated context) once the parent job is cancelled and the lambda is yet to start execution on the underlying dispatcher? Consider example:

class Foo {
    val dispatcher// An android handler thread as a Coroutine Dispatcher
    val job // Parent Job
    val coroutineScope = job + dispatcher

    fun <T> run(block: () -> T) {
        // some prechecks
        return runBlocking(coroutinScope.coroutineContext) {
            // this runs on dispatcher
        }
    }

    fun shutdown() {
       // stop underlying runBlocking 
       job.cancel()
    }
}

Consider the handler thread is busy doing some other stuff and runBlocking is waiting for it to finish. Meanwhile shutdown() gets invoked. Is there a way to 'cancel/stop' this runBlocking call? (Without using thread interrupts, although once lambda has started execution cancellation becomes cooperative).

[Melih Aksoy]

Is this before it’s reached or after it starts doing some work but before completes ?

[Melih Aksoy]

AFAIK runBlocking will be cancelled with context you provide and end up with JobCancellationException.

[winchester044]

Its after control reaches runBlocking and current thread is blocked. But runBlocking is waiting for the dispatcher to become free (its busy doing something else), so, 'actual' execution is yet to start.