안드로이드 코루틴 async, await

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers.IO
import kotlinx.coroutines.Dispatchers.Main
import kotlinx.coroutines.async
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch


class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        CoroutineScope(Main).launch {
            Log.i("MyTag","Calculation started....")

            val stock1 = async(IO) {
                getStock1()
            }
            val stock2 = async(IO) {
                getStock2()
            }

            val total = stock1.await()+stock2.await()
            Toast.makeText(applicationContext,"Total is $total",Toast.LENGTH_LONG).show()
            
        }

    }
}

private suspend fun getStock1() : Int {
    delay(10000)
    Log.i("MyTag"," stock 1 returned ")
    return 55000
}

private suspend fun getStock2() : Int {
    delay(8000)
    Log.i("MyTag"," stock 2 returned ")
    return 35000
}