CoroutineScope Dispatchers.IO asynchronous operation async return function, Kotlin

CoroutineScope Dispatchers.IO asynchronous operation async return function, Kotlin

 

 

 

import kotlinx.coroutines.*

fun myFun(a: Int, b: Int, retFun: (sum: Int) -> Unit) {
    println("分支myFun开始... ${System.currentTimeMillis()}")
    val task = CoroutineScope(Dispatchers.IO).async(start = CoroutineStart.LAZY) {
        println("myFun delay... ${System.currentTimeMillis()}")
        delay(3000)
        println("myFun delay end ${System.currentTimeMillis()}")
        a + b
    }

    CoroutineScope(Dispatchers.IO).launch {
        println("myFun launch... ${System.currentTimeMillis()}")
        val sum = task.await()
        retFun(sum)
        println("myFun retFun ${System.currentTimeMillis()}")
    }
    println("分支myFun结束 ${System.currentTimeMillis()}")
}

fun main(args: Array<String>) {
    println("主流程开始 ... ${System.currentTimeMillis()}")
    myFun(1, 2) { sum ->
        println("主流程等待结果返回...")
        println("main : $sum ${System.currentTimeMillis()}")
        println("主流程结果返回")
    }
    println("主流程结束 ${System.currentTimeMillis()}")


    Thread.sleep(5000)
}

 

 

 

The main process starts... 1703757127994
Branch myFun starts... 1703757127995
Branch myFun ends 1703757128042
The main process ends 1703757128042 myFun
launch... 1703757128045 myFun
delay... 1703757128046
myFun delay end 1703757 131050
The main process is waiting for the result to be returned...
main : 3 1703757131052
The main process result returns
myFun retFun 1703757131052

Process finished with exit code 0