This is a little example of how to compose two coroutines (IO) to work concurrently and to make parent coroutine to suspend in await calls

kotlin-coroutines-example-01.kt

import kotlinx.coroutines.*

fun main() {
    
    GlobalScope.launch  {
        println("[${Thread.currentThread().name}] Before asyncs")
        val one = async (Dispatchers.IO) { doSomething1() }
        val two = async (Dispatchers.IO) { doSomething2() }
        println("[${Thread.currentThread().name}] After asyncs")
        println("[${Thread.currentThread().name}] The answer is ${one.await() + two.await()}")
        println("[${Thread.currentThread().name}] After awaits")
    }
    
    println("[${Thread.currentThread().name}] Sleeping before exiting...")
    Thread.sleep(2000L)
    println("[${Thread.currentThread().name}] Exit")
}

suspend fun doSomething1(): Int {
    delay(100L) // pretend we are doing something useful here
    println("[${Thread.currentThread().name}] doSomething1")
    return 13
}

suspend fun doSomething2(): Int {
    delay(1000L) // pretend we are doing something useful here, too
    println("[${Thread.currentThread().name}] doSomething2")
    return 29
}

//Output executing program in Kotlin Playground  https://play.kotlinlang.org/  
//OUTPUT 
//[main] Sleeping before exiting...
//[DefaultDispatcher-worker-1] Before asyncs
//[DefaultDispatcher-worker-1] After asyncs
//[DefaultDispatcher-worker-2] doSomething1
//[DefaultDispatcher-worker-1] doSomething2
//[DefaultDispatcher-worker-1] The answer is 42
//[DefaultDispatcher-worker-1] After awaits
//[main] Exit

This is a little example of how to compose two coroutines (IO) to work concurrently and to make parent coroutine to suspend in await calls