I want an

actor

that I can cancel and restart. Is that possible?

@zak.taccardi Only if you swap the actor and point to the new reference, or if you implement a

SendChannel

that delegates to an

actor

you can swap from under.

hmm that seems kind of messy

Or you can make your actor accept a cancel but not too hard signal, then make it accept a restart now signal. You could launch coroutines inside of it and cancel this previously running coroutine when such a signal arrives

I’ll explain my use case. - I want to kick off some long running work on demand. - If a request comes in to kick off this long running work while it’s already running, I want to cancel the existing coroutine that is doing the long running work, and restart it. - I never want two instances of the long running work to be done in parallel

@zak.taccardi Oh I see, I remember someone in this channel already helped me solve this problem. Here's an extension you can use as is in your `actor`: https://github.com/LouisCAD/Splitties/blob/8d1b5224bc1b17c06933f50ec3c0d3faa6d7ebf6/sample/src/main/kotlin/com/louiscad/splittiessample/extensions/coroutines/Channels.kt#L32

As a note from other talks, don't you want to avoid using

suspend

and extend

CoroutineScope

at the same time? The action looks like it should be just

suspend

since it's long running

oh that’s obvious! just put a

launch

inside the

actor

Use an actor to start/cancel coroutines for the long running job. Then it gets free immediately.

@Allan Wang The linked function (named

consumeEachAndCancelPrevious

) is just a suspend function and creates its own local scope. The other one above it is a solution to this issue: https://github.com/Kotlin/kotlinx.coroutines/issues/328

my solution to this is here: https://kotlinlang.slack.com/archives/C1CFAFJSK/p1545945904107900 (though that lead me to my next problem). Thanks!