Is there any elegant way to bind multiple channels to the si

Question

Is there any elegant way to bind multiple channels to the single scope I m trying to make an actor that receives and processes data from multiple channels ``` launch val channelA = openChannelA val channelB = openChannelB val channelC = openChannelC while isActive select channelA onReceive channelB onReceive channelC onReceive ``` However I also want all of those channels closed if the actor is terminated for any reason

Matej Drobnič · Answer

From what I can see `consume` does that but it is very ugly ``` launch val channelA = openChannelA val channelB = openChannelB val channelC = openChannelC channelA consume channelB consume channelC consume while isActive select channelA onReceive channelB onReceive channelC onReceive ```

gildor · Answer

Implementation with consume is incorrent it will essentially consume them one by one

gildor · Answer

select is right way to do that

gildor · Answer

you also can just set select using forEach on list of channels to avoid duplication

gildor · Answer

also you can use whileSelect

Matej Drobnič · Answer

right but if I just use select channels will not close when coroutine cancels

Marko Mitic · Answer

Channels don t have scopes but coroutines sending the data using channel do

Marko Mitic · Answer

So if `openChannelA B C ` launches a coroutine in same scope as actor all those will be canceled with the actor and your channels will be garbage collected eventually

gildor · Answer

just close channels in context Job invokeOnCompletion inside your launch

gildor · Answer

but even better open channel using produce on `launch` scope as Marko suggesting

Matej Drobnič · Answer

`openChannelA ` do not perform any launchers

Matej Drobnič · Answer

for example `Flowable openSubscription ` from rx integration is not scope aware

Marko Mitic · Answer

try finally should work not sure how elegant it is

gildor · Answer

gt for example `Flowable openSubscription ` from rx integration is not scope aware Do not use it instead use Flowable asFlow that it will be perfectly lifecycle safe and scope aware Channel is actually bad wrapper for Flowable

Matej Drobnič · Answer

does flow support select though

gildor · Answer

There is no select for Flow there are much better operators like merge zip concat depending on your use case

Matej Drobnič · Answer

not sure any of those fits my use case of creating an actor

gildor · Answer

if you have N Flowable it s very easy to create N Flow from them and listen all events and receive them when first of them available like with single listener for multiple selects Again you do not show example how you use it in actor if you just do the same kind operatio is just `flattenMerge ` operator

Matej Drobnič · Answer

all flows are different

Matej Drobnič · Answer

every one of them has different type and different logic

Matej Drobnič · Answer

so I can t just merge them

gildor · Answer

Okay do not merge them just collect all of them separately or just move your logic to onEach operator of each flow and than use launchIn myScope where myScope is scope of your actor everything will be correctly connected by structured concurrency

Matej Drobnič · Answer

But wouldn t that process them in parallel instead of single sequence like the actor example above

gildor · Answer

depends on how you use them it will run in parallel but as I said you can merge them with some wrapper for every type