父挂起函数中的这些挂起函数会按顺序运行吗？

Question

The Code A is from the artical https://codelabs.developers.google.com/codelabs/kotlin-coroutines/#3

Will these suspend functions inside in a parent suspend function be run in sequence?

The system run and get the result of val slow first, then run and get the result of val another , finally it run database.save(slow, another) , right ?

Code A

@WorkerThread
suspend fun makeNetworkRequest() {
    // slowFetch and anotherFetch are suspend functions
    val slow = slowFetch()
    val another = anotherFetch()
    // save is a regular function and will block this thread
    database.save(slow, another)
}

// slowFetch is main-safe using coroutines
suspend fun slowFetch(): SlowResult { ... }
// anotherFetch is main-safe using coroutines
suspend fun anotherFetch(): AnotherResult { ... }

Answer 1

Yes, Kotlin suspending functions sequential by default .

To run them in parallel you have to use async-await .

Answer 2

as document says...

it is Sequential by default

suspend fun taskOne(): Int {
    delay(1000L)
    return 5
}

suspend fun taskTwo(): Int {
    delay(1000L)
    return 5
}

val time = measureTimeMillis {
    val one = taskOne()
    val two = taskTwo()
    println("The total is ${one + two}")
}

println("time is $time ms")

//output
//The total is 10
//The total 2006 ms

you can do it Concurrent using async

suspend fun taskOne(): Int {
    delay(1000L)
    return 5
}
    
suspend fun taskTwo(): Int {
    delay(1000L)
    return 5
}
    
val time = measureTimeMillis {
    val one = async { taskOne() }
    val two = async { taskTwo() }
    println("The total is ${one.await() + two.await()}")
}

println("time is $time ms")

//output
//The total is 10
//The total 1016 ms