kotlin_fundamentals_11.kt

fun main() {
    // Thread: Main
    // Builder explanation: runBlocking is used for bridging coroutine 
    //      code to normal code.
    //      It blocks the thread calling it until it's execution is complete.
    //      We call our taskT() on main thread and launch coroutines inside it.
    //      It returns the coroutine job as result.
    runBlocking {
        val parentCoroutineC = taskT()

        // Join has to be used for example purposes otherwise the program 
        // will complete before 'T' completes.
        // 
        // This is because since 'T' is a fire and forget task, we start it 
        // with launch coroutine builder which will return instantly with 
        // the representative job 'C' and the execution of this 
        // block will be complete.
        // Also because since T is launched with a global scope, th
        // So to wait for 'C' to complete we wait until it joins.
        
        // Also note that since we start 'C' in GlobalScope 
        // it's not a child of the scope provided by the runBlocking. 
        // Hence the parent-child relationship doesn't apply.
        parentCoroutineC.join()
    }
    println("Exiting main()")
    exitProcess(0)
}