```someList.forEach { GlobalScope.launch { ...

# coroutines

[Timur Atakishiev]

someList.forEach {
    GlobalScope.launch {
        if (validator.validate(it)){
            someStorage.add(it)
        }
    }
}

Hi guys, I am expecting that validate function is going to be excecuted in N numbers(N = size of someList) of coroutines. hewever, my application is working sequentialy, first it is validating first element, second element and so on. Should it work sequentially? Or am I doing something wrong?

[paulex]

Sorry, why do you really have to launch for each item?

[Timur Atakishiev]

since it is long running process, I decide to use coroutines, if result is going to be as I want, size of collection = number of calling validate function, I want to show my team that we can start to use coroutines in our project

[paulex]

Hi, @Timur Atakishiev I'm new to coroutines but i don't think it's going to run sequentially...

I've written a small code to simulate this..

import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

suspend fun addAfterValidate(n:Int){
    delay(3000L)
    println("validating $n\n")
}

arrayListOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).forEach { 
    GlobalScope.launch { 
        addAfterValidate(it)
    }
}

[paulex]

This is the response...

[Timur Atakishiev]

But at my case it is working sequentially, I don`t know why. validate function is making some long running process. In My case there are 5 parallel calls of validate and then it is waits till one of that 5 parallel calls is going to be end

[paulex]

perhaps validate function is a blocking call

[Timur Atakishiev]

validate is using RestTemplate, and makes some get request certain URI, is it blocking scope?

[Timur Atakishiev]

coroutineScope {
    someList.forEach {
        launch(Executors.newSingleThreadExecutor().asCoroutineDispatcher()) {
            if (validator.validate(it)) {
                <http://log.info|log.info>("validator called on $it")
                someStorage.add(it)
            }
        }
    }
}

Found a solution for my problem, who knows whether it is okay or not?