I'm new to kotlin and its concept coroutine.
I have below coroutine using withTimeoutOrNull -
import kotlinx.coroutines.*
fun main() = runBlocking {
val result = withTimeoutOrNull(1300L) {
repeat(1) { i ->
println("I'm with id $i sleeping for 500 ms ...")
delay(500L)
}
"Done" // will get cancelled before it produces this result
}
println("Result is $result")
}
Output -
I'm sleeping 0 ...
Result is Done
I have another coroutine program without timeout -
import kotlinx.coroutines.*
fun main() = runBlocking {
val result = launch {
repeat(1) { i ->
println("I'm sleeping $i ...")
delay(500L)
}
"Done" // will get cancelled before it produces this result
}
result.join()
println("result of coroutine is ${result}")
}
output -
I'm sleeping 0 ...
result of coroutine is StandaloneCoroutine{Completed}@61e717c2
How can I get the result of computation in kotlin coroutine when I don't use withTimeoutOrNull like my second program.
launch does not return anything, so you have to either:
Use async and await (in which case, await does return the value)
import kotlinx.coroutines.*
fun main() = runBlocking {
val asyncResult = async {
repeat(1) { i ->
println("I'm sleeping $i ...")
delay(500L)
}
"Done" // will get cancelled before it produces this result
}
val result = asyncResult.await()
println("result of coroutine is ${result}")
}
Not use launch at all or move your code that is inside the launch into a suspending function and use the result of that function:
import kotlinx.coroutines.*
fun main() = runBlocking {
val result = done()
println("result of coroutine is ${result}")
}
suspend fun done(): String {
repeat(1) { i ->
println("I'm sleeping $i ...")
delay(500L)
}
return "Done" // will get cancelled before it produces this result
}