How could I check if a singlethreaded coroutine context is currently executing or not?

# coroutines

[coder82]

How could I check if a singlethreaded coroutine context is currently executing or not?

[coder82]

I creatd it with newSingleThreadContext("name")

[gildor]

What is your use case for it?

[coder82]

I want a single thread to which I queue tasks, and if a task is already executing I don't want to queue another task, rather, do something else like printing a message

[coder82]

Essentially, I have 2 tasks, and they must go 1 at a time, if user tries to execute them in parallel I need to print a message.

[coder82]

So I thought to check "isActive" on a shared single thread context, but it doesn't work

[gildor]

Oh, I think that it’s completely wrong approach to queue coroutine tasks

[gildor]

You cannot use single thread for this

[gildor]

because coroutine do not block thread, this would make the whole idea of asynchronous API useless

[gildor]

so obviously you cannot limit amout of running coroutine on thread

[gildor]

instead of thread you can use actor, which is just a single coroutine that has message channel and process each of them sequentially

[gildor]

I don’t want to queue another task

If you don’t need queue, just 1 is running and all other are dropped, you can use offer method which returns false if channel is already full and message will be just lost

[coder82]

yep makes sense

[gildor]

See more details here
https://github.com/Kotlin/kotlinx.coroutines/blob/master/docs/shared-mutable-state-and-concurrency.md#actors