Coroutines I : The Subtle Bliss Of Coroutines

This is the first talk in a four edition series that focuses on becoming good with coroutines. This talk is a gentle introduction to coroutines and what problem they're trying to solve and why. It also shows the audience how to run coroutines.

Transcript

1. The Subtle Bliss of Coroutines @mambo_bryan 01
2. 02 Design Centric Engineer Brian Odhiambo Dishwasher @ Baobab Circle Co-organizer @ KotlinKenya Maintaining @ KotlinBits Yeah am all about that UI/UX & Kotlin
3. HOW How to use coroutines WHY Why use coroutines The World of Concurrency 03 WHAT What are coroutines synchronous! asynchronous! structured!
4. The WHAT? What are coroutines
5. Works concurrently with the rest of the code Similar to threads but lightweight Is not tied to any thread Expressed in a structured way What are coroutines? An instance of suspendable computation
6. An Example Coroutines marked with suspend import kotlinx.coroutines.* suspend fun main() { println("Starting Work") doWork() } suspend fun doWork(){ delay(1000) println("Finished Work") } Starting Work Finished Work 06
7. The WHY? Why coroutines
8. Prevents the callback hell problem Easily maintainable & scalable Gives you more control of how you handle jobs Less resource intensive than JVM threads (2mb) Why Coroutines ? sendRequest( onSuccess = { sendAnotherRequest( onSuccess = {...}, onFailure = {...}, ) }, onFailure = {...} )
9. Why Coroutines ? FROM : sendRequest( onSuccess = { sendAnotherRequest( onSuccess = {...}, onFailure = {...}, ) }, onFailure = {...} ) TO : val result = sendRequest() if(response != null){ val result = sendAnotherResponse() ... } ...
10. The HOW? How do you coroutine
11. Example custom coroutine marked with suspend import kotlinx.coroutines.* fun main() { println("Starting Work") GlobalScope.launch { doWork() } Thread.sleep(2000) } suspend fun doWork(){ delay(1000) println("Finished Work") } Starting Work Finished Work 11
12. Example II custom coroutine marked with suspend import kotlinx.coroutines.* fun main() { println("Starting Work | ${Thread.currentThread().name}") GlobalScope.launch { doWork("1") } CoroutineScope(Dispatchers.IO).launch { doWork("2") } Thread.sleep(3000) } suspend fun doWork(name: String){ delay(1000) println("Finished Work $name | ${Thread.currentThread().name}") } Starting Work | main Finished Work 1 | DefaultDispatcher-worker-2 @coroutine#1 Finished Work 2 | DefaultDispatcher-worker-2 @coroutine#2 12
13. Next Session Advanced Coroutine Concepts
14. Jobs What are Jobs and what is their lifecycle... Builders How can you use builders to create coroutines Advanced Coroutine Concepts 14 Contexts What are contexts and what is context switching and so much more!
15. One Last Thing For the community
16. KotlinBits 😎 A fun and easy way to learn Kotlin in small bits and pieces. React, Comment & Share kotlinbits.vercel.app
17. 16 mambo_bryan MamboBryan Thank you! Have a nice Kotlin KotlinBits kotlinbits.vercel.app