A gentle introduction to Kotlin Coroutines

Transcript

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   A gentle introduction to Kotlin Coroutines Arturo Mejia Twitter: @ArturoMejia481

   ArturoMejiaMarmol.com
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   None
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   Alternatives @ArturoMejia481 Threads Callbacks RX (Reactive extensions) Futures Promises

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

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

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   Callbacks @ArturoMejia481 Callback Hell

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

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   Callbacks @ArturoMejia481 Difficult error handling.

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   Promises and Futures @ArturoMejia481

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    Reactive Extensions @ArturoMejia481 You have to change the way that

    you approach a problem. Operators RX Schedulers Streams
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    @ArturoMejia481 Reactive Extensions

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    @ArturoMejia481 Kotlin Coroutines Do async work the same way, exceptions,

    loops, etc…
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    @ArturoMejia481 Kotlin Coroutines Clear differences between suspend functions

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    @ArturoMejia481 Kotlin Coroutines Same function signature

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    Coroutines = Lightweight @ArturoMejia481 Threads Coroutines

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    @ArturoMejia481 Kotlin Coroutines

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    Goal @ArturoMejia481 Suspend Dispatchers Coroutine Builders Launch Async/await

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    Suspend @ArturoMejia481 A key word to indicate the compiler that

    a function can be suspended.
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    Suspend @ArturoMejia481 A suspend function should be called from a

    coroutine or another suspend function.
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    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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    @ArturoMejia481 Coroutine ≈ Threads

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    Let’s get our hands dirty! @ArturoMejia481

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    Launch @ArturoMejia481 Launch is when we want to fire and

    forget.
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    Async @ArturoMejia481 Async is when we want to run something,

    then await the result.
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    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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    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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    “With a great power, comes responsibility” @ArturoMejia481 Spiderman

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    Questions? @ArturoMejia481

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