AsyncIoThread.kt

import kotlinx.coroutines.sync.Semaphore
import java.util.concurrent.Executors
import java.util.concurrent.atomic.AtomicReference

object AsyncIoThread {

    private val executor = Executors.newCachedThreadPool { run ->
        val thread = Thread(run)
        thread.name = "AsyncIoThread-${thread.name}"
        thread.isDaemon = true
        thread
    }

    /**
     * Coroutine will be suspended,
     * but code will be executed on separate thread and coroutine scope stays not thread-blocking.
     */
    suspend fun <A> runIsolatedSync(
        code: () -> A
    ): A? {
        val res = AtomicReference<A?>(null)
        val semaphore = Semaphore(1, 1)
        executor.submit {
            res.set(code())
            semaphore.release()
        }
        semaphore.acquire()
        return res.get()
    }
}