Execute coroutines in parallel and wait for result of all coroutines.

ParallelExecution.kt

import kotlinx.coroutines.*
import kotlin.random.Random
import kotlin.system.measureTimeMillis

fun main(args: Array<String>) {
    val time = measureTimeMillis {
        runBlocking {
            val coffeePowder = async {
                println("Grinding coffee bean...")
                grindCoffeeBeans()
            }
            val hotMilk = async {
                println("Heating milk...")
                heatMilk()
            }
//        val ingredient1 = coffeePowder.await()
//        val ingredient2 = hotMilk.await()
            val (ingredient1, ingredient2) = awaitAll(coffeePowder, hotMilk)
            println("$ingredient1 + $ingredient2 = Hot Coffee!")
        }
    }
    println("Time ${time / 1000}s")
}

suspend fun grindCoffeeBeans(): String {
    delay(1000)
    return "Coffee powder"
}

suspend fun heatMilk(): String {
    delay(1000)
    return "Hot Milk"
}