```launch(context + job1 + job2){}``` is it possib...

# coroutines

[deviant]

launch(context + job1 + job2){}

is it possible to use 2 different parents to control child lifecycle? well, i know it's not. but what best way to achieve such functionality?

[kirillrakhman]

I guess you could start two separate couroutines, join them to the parent jobs. and when one of them terminates, cancel the child

[deviant]

i want to use job1 and job2 just for cancellation signal for the 1 child. job1 take care of activity lifecycle (cancel on onStop) and job2 is some hand made control for the childs using it.

[kirillrakhman]

maybe use invokeOnCompletion?

[deviant]

i think its better to use actor model with cancellation event

[kirillrakhman]

and check if the exception is a CancellationException

[deviant]

maybe use invokeOnCompletion?

afraid to drown in boilerplate 🙂

[hackerham]

why not create two contexts?

[hackerham]

one will be suspended indefinitely, the other will work

[hackerham]

if you cancel first job, second will be cancelled too

[hackerham]

that will work two ways
1. you can use two "async" to create jobs, one will be parent of another
2. you can create two jobs, parent and child, manually and then pass it to launch

[deviant]

could you please show simple code example? not sure i understood correctly.

[hackerham]

var job2 = null;
val job1 = async(start=true) {
   job2 = async(start=true) {
      //do stuff
   }
   job2.onComplete { job1.cancel() }
   suspendCoroutine<Unit> { cont -> /* it never ends BWAHHAHA */ }
}

[hackerham]

something like that

[hackerham]

the idea is that job1.cancel() also cancels job2 because they are related

[deviant]

thanks, Ivan. this nesting job1->job2 looks not very flexible though

[deviant]

anyway i've managed my task with 1 parent job instead of 2

[hackerham]

I'm happy for you 🙂