``` val result = async myContext doSomething await vs val re kotlinlang #coroutines

``` val result = async(myContext) { doSomething() ...

bdawg.io

08/14/2018, 5:19 PM

Copy code

val result = async(myContext) { doSomething() }.await()
// vs
val result = withContext(myContext) { doSomething() }

igorvd

08/14/2018, 5:29 PM

In this case you should go with the

WithContext

the

async

is useful for parallelism and to cancel the coroutine

💯 1

withoutclass

08/14/2018, 5:35 PM

Intellij even has an intention to convert from immediately awaiting over to

withContext

Vsevolod Tolstopyatov [JB]

08/14/2018, 6:01 PM

the rule of thumb: if you are not sure, use

withContext

🙂

➕ 3

igorvd

08/14/2018, 6:57 PM

I don't know how the docs are, but when I was learning coroutines, I don't remember reading anything that mentions the

withContext

.. What I remember is the docs encouraging you to use

async-await

when you want an asynchronous result

elizarov

08/14/2018, 7:45 PM

You use

async-await

for concurrent decomposition (do many async and wait for all them). If you want asynchronous result, you just invoke a suspending function.

uli

08/14/2018, 7:51 PM

Depending on when you read about coroutines you probably read about

run

which was basically renamed to

withContext

v0ldem0rt

08/14/2018, 7:59 PM

Async results can be used by many coroutines in parallel as well; you can achieve cool stuff like https://blog.doordash.com/avoiding-cache-stampede-at-doordash-55bbf596d94b

👍 1

elizarov

08/15/2018, 6:29 AM

Yes. You can use the for “async lazy”

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