core/kotlinx-coroutines-core/test/guide/example-compose-04.kt

/*
 * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
 */

// This file was automatically generated from coroutines-guide.md by Knit tool. Do not edit.
package kotlinx.coroutines.experimental.guide.compose04

import kotlinx.coroutines.experimental.*
import kotlin.system.*

suspend fun doSomethingUsefulOne(): Int {
    delay(1000L) // pretend we are doing something useful here
    return 13
}

suspend fun doSomethingUsefulTwo(): Int {
    delay(1000L) // pretend we are doing something useful here, too
    return 29
}

// The result type of somethingUsefulOneAsync is Deferred<Int>
fun somethingUsefulOneAsync() = async {
    doSomethingUsefulOne()
}

// The result type of somethingUsefulTwoAsync is Deferred<Int>
fun somethingUsefulTwoAsync() = async {
    doSomethingUsefulTwo()
}

// note, that we don't have `runBlocking` to the right of `main` in this example
fun main(args: Array<String>) {
    val time = measureTimeMillis {
        // we can initiate async actions outside of a coroutine
        val one = somethingUsefulOneAsync()
        val two = somethingUsefulTwoAsync()
        // but waiting for a result must involve either suspending or blocking.
        // here we use `runBlocking { ... }` to block the main thread while waiting for the result
        runBlocking {
            println("The answer is ${one.await() + two.await()}")
        }
    }
    println("Completed in $time ms")
}