How not to write coroutines

bad_coroutine_usage.kt

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

fun performBlockingOperation(jobName: String) {
    // Simulating a blocking operation
    Thread.sleep(1000)
    println("Blocking operation completed. jobName = $jobName, thread : ${Thread.currentThread().name}")
}

fun main() = runBlocking {
    val executionTime = measureTimeMillis {
        val job1 = launch {
            performBlockingOperation("job1")
        }
        val job2 = launch {
            performBlockingOperation("job2")
        }
        val job3 = launch {
            performBlockingOperation("job3")
        }
        println("Coroutine launched")
        joinAll(job1, job2, job3)
    }
    println("Total execution time: $executionTime ms")
}

/*
Console Output:

Coroutine launched
Blocking operation completed. jobName = job1, thread : main
Blocking operation completed. jobName = job2, thread : main
Blocking operation completed. jobName = job3, thread : main
Total execution time: 3020 ms // this value(3020) may change but should be slightly greater than 3000ms.
*/