A gentle introduction to Kotlin Coroutines

Sample Code: https://github.com/Amejia481/kotlin_coroutine_intro

Transcript

1. A gentle introduction
   to Kotlin Coroutines
   Arturo Mejia
   
   Twitter: @ArturoMejia481
   
   ArturoMejiaMarmol.com
   

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3. Alternatives
   @ArturoMejia481
   Threads
   
   Callbacks
   
   RX (Reactive extensions)
   
   Futures
   
   Promises
   

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4. Threads
   @ArturoMejia481
   Expensive, not easy to use.
   IOS deprecate threads. DispatchQueue
   
   

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5. Callbacks
   @ArturoMejia481
   Don't call me, I'll call you!
   

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6. Callbacks
   @ArturoMejia481
   Callback Hell
   

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7. Callbacks
   @ArturoMejia481
   Callback Hell a.k.a Tilted Christmas Tree.
   
   

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8. Callbacks
   @ArturoMejia481
   Difficult error handling.
   

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9. Promises and Futures
   @ArturoMejia481
   

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10. Reactive Extensions
    @ArturoMejia481
    You have to change the way that you approach a problem.
    Operators
    RX
    Schedulers
    Streams
    

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11. @ArturoMejia481
    Reactive Extensions
    

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12. @ArturoMejia481
    Kotlin Coroutines
    Do async work the same way,
    
    exceptions, loops, etc…
    

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13. @ArturoMejia481
    Kotlin Coroutines
    Clear differences between suspend functions
    

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14. @ArturoMejia481
    Kotlin Coroutines
    Same function signature
    

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15. Coroutines = Lightweight
    @ArturoMejia481
    Threads
    Coroutines
    

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16. @ArturoMejia481
    Kotlin Coroutines
    

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17. Goal
    @ArturoMejia481
    Suspend
    
    Dispatchers
    
    Coroutine Builders
    
    Launch
    
    Async/await
    

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18. Suspend
    @ArturoMejia481
    A key word to indicate the compiler that a
    function can be suspended.
    

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19. Suspend
    @ArturoMejia481
    A suspend function should be called from a
    coroutine or another suspend function.
    

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20. Suspend
    @ArturoMejia481
    The Kotlin compiler transforms the function to a
    callback model and uses state machines to know
    when a function should be suspended or resume.
    

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21. @ArturoMejia481
    Coroutine ≈ Threads
    

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22. Let’s get our hands dirty!
    @ArturoMejia481
    

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23. Launch
    @ArturoMejia481
    Launch is when we want to fire and forget.
    

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24. Async
    @ArturoMejia481
    Async is when we want to run something, then
    await the result.
    

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25. Dispatchers
    @ArturoMejia481
    DEFAULT (Computational) Uses the # cores of the CPU, not
    good for computations like I/O, network, disk, etc.
    
    IO designed for doing blocking I/O operations, max #64
    thread, share the pool with DEFAULT.
    
    MAIN designed to operate UI objects.
    Indicate in which thread pool a coroutine should run
    

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26. Interoperate
    @ArturoMejia481
    kotlinx-coroutines-rx2: Utilities for Rx.
    
    kotlinx-coroutines-jdk8: Integration with JDK8
    CompletableFuture (Android API level 24).
    
    kotlinx-coroutines-android: Designed to operate UI objects.
    

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27. “With a great power, comes
    responsibility”
    @ArturoMejia481
    Spiderman
    

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28. Questions?
    @ArturoMejia481
    

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29. Thanks!
    Twitter: @ArturoMejia481
    ArturoMejiaMarmol.com
    Android Tutorials
    RayWenderLich.com/u/amejia481
    

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