kotlin-coroutines

kotlin-coroutine-scratch.kt

import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import java.time.LocalDateTime

fun printWithDatePrefix(msg: String) =
    println("${LocalDateTime.now()} : $msg")

suspend fun fetchItems(): List<String> {
    printWithDatePrefix("starting fetch")
    delay(5_000L)
    printWithDatePrefix("finished fetch")
    return listOf("a1", "a2", "a3")
}

suspend fun submitItem(item: String) {
    printWithDatePrefix("starting submit: $item")
    delay(2_000L)
    printWithDatePrefix("finished submit: $item")
}

runBlocking {
    printWithDatePrefix("starting")
    val items = fetchItems()
    items.forEach {
        launch {
            submitItem(it)
        }
    }
    printWithDatePrefix("after launching jobs")
}

printWithDatePrefix("finished")