KotlinConf 2018 - Exploring Coroutines in Kotlin by Venkat Subramaniam

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  • Опубліковано 23 гру 2024

КОМЕНТАРІ • 124

  • @GooksanGom
    @GooksanGom 4 роки тому +64

    Great, It really helped to understand coroutines.
    BTW, It's very impressive that he could keep talking without a break while he writes several lines of codes and runs it.
    There must have been coroutines running in his brain.

  • @canaldosouza4103
    @canaldosouza4103 6 років тому +80

    This guy is who made me start kotlin, greet to see him in the Kotlin Conf

  • @Codetutor-DemystifyCoding
    @Codetutor-DemystifyCoding 5 років тому +6

    This well co-ordinated explanation along with live coding demonstration is simply brilliant. He makes it look simple, but let me tell you, as some one who makes tutorials on UA-cam, this requires exceptional skills. Not just coding but presence of mind.

  • @ChetanSachdeva
    @ChetanSachdeva 6 років тому +78

    I've not seen anyone explaining the internals of coroutines better than Venkat Subramaniam.

    • @ViperCinema4D
      @ViperCinema4D 6 років тому +5

      ua-cam.com/video/YrrUCSi72E8/v-deo.html

    • @navsingh7934
      @navsingh7934 6 років тому +4

      he is the best speaker I have seen so far.

    • @aprofromuk
      @aprofromuk 3 роки тому +1

      no 1 can do that :)

  • @vasyan123
    @vasyan123 6 років тому +124

    I'm a simple man. I see Venkat Subramariam in a video title, I click.

    • @chukzydee
      @chukzydee 6 років тому +6

      Venkat and/or Florina on the title is enough to make me suspend all I'm doing and click on the video.

    • @salvatoreshiggerino6810
      @salvatoreshiggerino6810 6 років тому +1

      To click is to do the needful

    • @j-r-hill
      @j-r-hill 5 років тому

      It's so true

    • @AmarPoonia
      @AmarPoonia 5 років тому

      Same here.. even if I've watched it before, it's so satisfying

    • @gleb.ignatev
      @gleb.ignatev 3 роки тому

      @@chukzydee suspend, you're saying, I see what you did here...

  • @norulesprateek
    @norulesprateek 4 роки тому +5

    What a great explanation! You know he is an absolute professional when he shows how suspend functions are sending the rest of the code (Continuation) of the function as a parameter 28:24 . Everything including async block explanation was just great. He taught me things he wasn't even trying(possibly) to cover in this conf. Thanks!

  • @VedantRajdeep
    @VedantRajdeep Рік тому +3

    That's some introduction. I like how he explained the "Why?" part of the changes.

  • @benjaminrangel5313
    @benjaminrangel5313 6 років тому +11

    I love Venkat voice, it is so calming.

  • @KaranSharmak4c6
    @KaranSharmak4c6 2 роки тому +2

    Good examples. the multitasking while presentation using vim is incredible. !! Also the sound of claps at end of video says it all.

  • @yasserakbbach7342
    @yasserakbbach7342 3 роки тому +4

    I refer to Venkat's lectures whenever I get to the mood of seeking out wisdom 😌

  • @jimmyleo5414
    @jimmyleo5414 4 роки тому +17

    What a god damn pro, sometimes I need to pause to think about what he said

    • @0xmg
      @0xmg 4 роки тому +8

      The buffering does that for me

    • @thecoderui
      @thecoderui 3 місяці тому

      ​@@0xmg So lucky!

  • @mehmoodrehman6336
    @mehmoodrehman6336 2 роки тому +1

    Topics:
    1. Parallel vs Asynchronous 0:50 (Java, Kotlin ahead of Java at least 5-years, Microservices, sequential vs parallel) coroutines make it easy to write asynchronous code.
    2. Concurrency vs non-blocking 1:50 (Java example and comparison)
    3. Let's examine parallel just a bit, in Java 2:30 (Java example and comparison)
    Parallel Stream:
    Structure of [functional] sequential code
    is the same as parallel code
    Coroutine:
    Structure of [Imperative] Synchronous code
    is the same as asynchronous code
    4. Why not be happy with that? 5:20
    5. Functional style is awesome 5:20
    6. But, handling exceptions is a mess 5:44
    7. Coroutines are asynchronous 6:25

    launch { //launch () method
    }
    8. From synchronous to asynchronous 9:00
    Non-blocking GUI's
    9. Blocking to non-blocking 10:12
    10. How do coroutines work? 10:12
    11. A sequential code 17:14
    12. Using suspend 23:20, 24:30
    Parallel Stream:
    Structure of [functional] sequential code
    is the same as parallel code
    Coroutine:
    Structure of [Imperative] Synchronous code
    is the same as asynchronous code
    13. Doing asyn 33:00

  • @anshsachdeva850
    @anshsachdeva850 3 роки тому +1

    This was so captivating. i didn't even felt for a minute that am staring at my screen for 44 minutes. amazing presentation.
    Anyone reading this comment in 2021 : How to access the launch{} function in coroutines 1.5?

  • @aksh1618
    @aksh1618 3 роки тому

    What a legend. Solved so many queries I had about coroutines with such simple but precise and amazing explanations.

  • @methodsignature
    @methodsignature 5 років тому +14

    I've never seen anyone program in VI before. It felt a bit like black magic.

  • @a0um
    @a0um 6 років тому +4

    Great presentation.
    I really appreciated the use of bare bone editors and the love coding.
    I wish he slowed down a bit around the crucial points but understand it's a lot to cover in the given time.
    Impressive how he kept going confidently despite the inevitable typos, etc.
    I still have some questions about coroutines but this talk really gave me some good examples to think about.

  • @thegreatestdao
    @thegreatestdao 5 років тому +1

    This guys speech is so captivating!

  • @Nithr1s
    @Nithr1s 5 років тому +2

    Just so you know, there is an error in explanation of "suspend" modifier. Explanation by Roman Elizarov could be found here: medium.com/@elizarov/blocking-threads-suspending-coroutines-d33e11bf4761

  • @leomak7580
    @leomak7580 2 роки тому

    the best speaker ever ) java versions are bumping, new langs come and go. but Venkat is a guy who always was with us )

  • @antosha4e
    @antosha4e 6 років тому +5

    really like a way he explains stuff, his talk about DSLs also nice

  • @chrismakesgames9075
    @chrismakesgames9075 4 роки тому +1

    This talk was great. Thanks Venkat!

  • @johnyrufus
    @johnyrufus 3 роки тому

    That last example of step by step conversion from sequential -> suspend -> async did the trick for me :)

  • @rajushingadiya2860
    @rajushingadiya2860 2 роки тому +1

    Loved it

  • @tak68tak
    @tak68tak 4 роки тому +1

    He is really awesome. He is totally different from any other devs. It's like an entertainer or magician.

  • @dluxsoft2840
    @dluxsoft2840 Рік тому +1

    thanks sir ,best lecture on coroutine

  • @hassanalizadeh3492
    @hassanalizadeh3492 4 роки тому +1

    Amazing presentation

  • @hansmelo32
    @hansmelo32 5 років тому +2

    Every the venkat's videos make me to want to be a better developer 💪🏿. Great explanation!

  • @aikqboy
    @aikqboy 5 років тому

    He explains it so well and so simply. A very bright man.

  • @pums12
    @pums12 3 роки тому

    Just loved it. Thanks for this simple explanation

  • @KiumarsAbedian
    @KiumarsAbedian 5 років тому +1

    Amazing talk, but I am curious what the setup is being used for interactive Kotlin/Java coding in vi/vim

  • @Wengelef
    @Wengelef 6 років тому +1

    Venkat Superman

  • @DF-ss5ep
    @DF-ss5ep 2 роки тому

    The one and only.
    We meet again.

  • @terjemah_alquran
    @terjemah_alquran 5 років тому +1

    excellent excellent excellent

  • @karthikrpandian
    @karthikrpandian 5 років тому

    Amazing talk. Impressed by his coding and explanation going hand in hand.

  • @harshvardhanjoshi7445
    @harshvardhanjoshi7445 4 роки тому

    Great explanation. Must have been took months to find/create an example code which is this simple but very informative and covers almost everything. Great job.

  • @ImaginaryNumb3r
    @ImaginaryNumb3r 5 років тому

    @37:53 So this all is really just syntactic sugar for Thread pools and ComplteableFutures?

  • @МихаилСошников-в9р

    Отличная информация, спасибо большое!

  •  5 років тому +7

    "suspend modifier to a function makes it either asynchronous or non-blocking. " is not true according to the Roman Elizarov's article. medium.com/@elizarov/blocking-threads-suspending-coroutines-d33e11bf4761

  • @AlexPaluzzi
    @AlexPaluzzi 6 років тому

    One of the best talks I've watched in a long time.

  • @ashwin_mahajan
    @ashwin_mahajan 3 роки тому

    Great great presentation. 🙌

  • @thiagoalexandreee
    @thiagoalexandreee 6 років тому +1

    Amazing talk, thanks for the content!

  • @HermanBovens
    @HermanBovens 6 років тому +2

    I think I get coroutines now, but I'm not really sure why in the last part of the video, everything still needs to be in a launch {} block. Doesn't the suspend / async / await mechanism already make it asynchronous?

    • @vyli1
      @vyli1 6 років тому +1

      async {} can only be called from within a coroutine or a suspending function. In fact in the last example, the async call was not made from launch {} function, rather it was made from the lambda, that was passed as argument to the measure function.
      Since async {} can only be called from coroutine or a suspending function, he had to mark the lambda parameter from measure function as suspending.
      launch {} function is a coroutine builder. It hides lot of nontrivial code that you would have to write manually, if you wanted to write a coroutine.

    • @HermanBovens
      @HermanBovens 6 років тому

      @@vyli1 so the call to launch() is indeed unnecessary?

    • @vyli1
      @vyli1 6 років тому +4

      @@HermanBovens I'm sorry, I gave you a little bit misleading information. But first to answer your question, call to launch {} IS necessary.
      Originally I said, that async {} can only be called from coroutine or suspend function. This is not true, it can be called from wherever. However, .await() can only be called from coroutine or suspending function. Since in the code in the presentation we call .await() on result of async {} operation within lambda parameter, that lambda parameter MUST BE suspending lambda. (.await() can only be called from within a coroutine or suspending function).
      Since we've turned the lambda into a suspending function and we want to invoke the lambda from within measure function, we want to basically invoke a suspending function inside a nonsuspending function. That's not possible. Suspending functions can only be invoked from other suspending functions, or coroutines. Therefore, the measure function itself must be suspending.
      As I said before, suspend functions can only be called from within coroutines or another suspending functions. And we want to call the measure function. But measure function is suspending. Therefore we need to create a coroutine, from which we can call the measure function. That's why we do the call to launch {}.
      launch {} is a coroutine builder. It will build all the coroutine boilerplate code for us. So when we invoke our suspending function measure from within launch, our code will be executed within a coroutine, so the compiler will finally let us compile this code. There are other coroutine builders than launch, for example runBlocking {}, but in this case we didn't want to block the main thread, so that's why launch {} coroutine builder was chosen.
      When I said .await() can only be called from coroutine or another suspending function, what I mean is, compiler won't let you compile a code, where you'd want to invoke suspending function outside of a coroutine or a suspending function.

  • @pinoy_marites_beh
    @pinoy_marites_beh 2 роки тому

    I finally know what to do when someone asks me to put the status bar below the phone and the system back actions on top of the screen! Run for the exit!!!!!

  • @igrai
    @igrai 5 років тому +2

    Frankly, found it quite convoluted

  • @jesprotech
    @jesprotech 3 роки тому +1

    Extraodinarly goed presentation! Explaining everything from how we got here, why apply coroutines and the way to do that in Kotlin with great examples. I especially loved that last example where we can see how small changes in the code can make it asynchronous using coroutines. The yield example was really a great step in getting there to explain that. It really helped me to make it even more clear to me what coroutines actualy are, what they can do and where to use them.

  • @muhammadrahmatullahrahman1534
    @muhammadrahmatullahrahman1534 4 роки тому +2

    Venkat is such an awesome teacher

  • @hiteshchalise3988
    @hiteshchalise3988 5 років тому

    this was fantastic.

  •  6 років тому +4

    Instead of suspend measureTime you could have made it inline, i think it would work with await 😀 really nice talk btw, finally understood coroutines

    • @hhhapz
      @hhhapz 6 років тому +3

      I think the goal of the talk was to show how suspend functions make a difference, and allow thread blocking versus non-suspension functions.

  • @NafiulIslam
    @NafiulIslam 3 роки тому

    Great stuff!

  • @sagarghare9829
    @sagarghare9829 4 роки тому

    amazing and so engaging.

  • @JamielSheikh
    @JamielSheikh 5 років тому

    Excellent stuff, Venkat. Great explanations and witty humor.

  • @studyonline3236
    @studyonline3236 3 роки тому

    How is he auto-filling sentences ?

  • @bangoker
    @bangoker 6 років тому +1

    Great talk! I like that it was very concise, but I could offer one piece of feedback is to have longer pauses /paragraph breaks.
    It feels a little bit like a giant paragraph would read. There are sentences, but it there is no place to rest, its just one big big paragraph.

    • @methodsignature
      @methodsignature 5 років тому

      Yea, it felt a bit like catching a wave. If I didn't have much coroutine experience, I'm not sure I could have followed very well. Some of that was probably the time constraint of the setting.

  • @santanusur1265
    @santanusur1265 6 років тому

    If getting Google's stock price took "2 seconds" and Amzn's stock price took 1 second... Then for the last example Amazon's stock price would show up earlier right ?

  • @mohammedalzamil7191
    @mohammedalzamil7191 4 роки тому

    yes

  • @StasBar
    @StasBar 6 років тому

    Great presentation, great teacher!

  • @FrantisekNovak55
    @FrantisekNovak55 5 років тому

    isnt this all wrong?slapping suspend on a blocking call doesnt not make it async, its just synchronous within dispatcher thread from launch

  • @antoniokomangyudistira4150
    @antoniokomangyudistira4150 4 роки тому

    the " A sequential code" part is hard to understand :(

  • @Saketjsaket
    @Saketjsaket 4 роки тому

    Which IDE is he using to show the demo?

  • @smallufo
    @smallufo 5 років тому +1

    Live coding! Awesome!

  • @JohnPywtorak
    @JohnPywtorak 2 роки тому +1

    There are issues with this presentation, glossing over or missing key concepts. I would skip it if you are learning about coroutines. This was exploring, kinda, but really only the last 10 minutes are useful. The presenters book is decent, but this was not a good exploring talk. It appears I will be in the minority here. There are so few good coroutine talks, check out the Coroutines catch them all, best talk and maybe the only one.

  • @andre-vm
    @andre-vm 5 років тому +4

    3:10 HOLY MAMA! WATTA HELL IS GOIN' ON? (Nice talk, by the way. Good job!)

  • @igorg.8624
    @igorg.8624 6 років тому

    What do Coroutines offer that RxJava does not?

    • @RobertGolusinski
      @RobertGolusinski 6 років тому +2

      proandroiddev.com/kotlin-coroutines-vs-rxjava-an-initial-performance-test-68160cfc6723

    • @robchr
      @robchr 6 років тому +3

      It doesn't offer anything that RxJava cannot do. Coroutines can easily represent RxJava's Single and Maybe contexts but does not handle Observable streams without additional boilerplate. For some use cases where there would be a large number of concurrent requests like a server that has 100k+ concurrent connections, coroutines could be more memory efficient since it requrires less intermediate objects (lambdas). Coroutines represent a single chain in a single object that acts like a state machine.

    • @igorg.8624
      @igorg.8624 6 років тому +2

      ... although I must say - sequence continuations in Coroutines are super simple to reason about and much easier to teach to a newbie than RxJava

    • @GK-rl5du
      @GK-rl5du 6 років тому +4

      It doesn't offer anything new as compared with RxJava or even any callback+eventloop models. The main promise of coroutines is that one can write syncrhonous looking code which the runtime executes concurrently. On the other hand, consider Rx... one has to be familiar with the core Rx interfaces like Observable... although this approach was much better than callback hell.. esp considering exception handling.. there's still a learning curve. Coroutines on the other hand will bring concurrency to where you are.

    • @FrantisekNovak55
      @FrantisekNovak55 5 років тому

      I love rx, but flatmapping singles is stupid and you need to always return tuples everywhere like an idiot

  • @jakubgwozdz2780
    @jakubgwozdz2780 6 років тому +2

    What is that, well, IDE?

    • @meribold
      @meribold 6 років тому +2

      That's a text editor. Probably TextMate.

    • @jakubgwozdz2780
      @jakubgwozdz2780 6 років тому

      I like the way it displays output at cursor.

    • @akashpatra19
      @akashpatra19 5 років тому

      @@jakubgwozdz2780 Yes, you have to configure. Long back after I saw his talk on Java Streams, I also configured like that. :)

  • @VivekMore1
    @VivekMore1 5 років тому

    You have the last name of Venkat spelled wrong in the title

  • @jobiraw
    @jobiraw 5 років тому

    is this man from pragimtech.com ?

    • @JetBrainsTV
      @JetBrainsTV  5 років тому

      No, we don't believe so. Dr. Venkat Subramaniam is the founder of Agile Developer, Inc. agiledeveloper.com

  • @animeshroy3746
    @animeshroy3746 4 роки тому +1

    VERY GOOD EXPLANATION...

  • @abubakrjabbarov2303
    @abubakrjabbarov2303 5 років тому

    A very good explanation, thank you!

  • @rIyAsE
    @rIyAsE 3 роки тому

    One of the best talk on coroutines (Y)

  • @edjinretrogamer
    @edjinretrogamer 3 роки тому

    Meu Deus, pare 1 segundo pra respirar!!!

  • @anmoldevgan7320
    @anmoldevgan7320 6 років тому +1

    Venkat is God of programming

  • @harshtiwari9588
    @harshtiwari9588 6 років тому

    Which editor does he use?

  • @siva_subramaniam
    @siva_subramaniam Рік тому

    Bm -16:58

  • @AjithKumar-vk1fw
    @AjithKumar-vk1fw 3 роки тому

    👍

  • @archiequinones6467
    @archiequinones6467 6 років тому

    Wow that was really good!! 😱😱 👏👏 just really wanna show my appreciation here 👏👏

  • @maxchin2
    @maxchin2 5 років тому +1

    He need pauses.

  • @VivekYadav-ds8oz
    @VivekYadav-ds8oz 4 роки тому

    This guy literally looks like my maths professor.

  • @_dinesh
    @_dinesh 3 роки тому

    TBH, Very hard to follow. Keep the sentences simple and the example simpler.

  • @jayasome199
    @jayasome199 2 роки тому

    27:00 Only moment, I can laugh.

    • @jayasome199
      @jayasome199 2 роки тому

      28:30 suspend bytecode -> Continuation

  • @conorsmall1373
    @conorsmall1373 Рік тому

    what a killer mustache

  • @rafihmahfooz5074
    @rafihmahfooz5074 6 років тому

    He changed camps, first Scala, now this lol

  • @syedtayyabulmazhar6945
    @syedtayyabulmazhar6945 4 роки тому +1

    He is coding and explaining at the same time. He is so async.

  • @nO_d3N1AL
    @nO_d3N1AL 6 років тому +1

    Not his best talk. Surprised and disappointed that he didn't compare coroutines to using threads directly and Futures. He didn't really say what co-routines add that we can't do since Java 5

  • @sundeepsharma6782
    @sundeepsharma6782 2 роки тому

    Sir, with due respect u have very nice knowledge but ur are speaking very fast, and hard to catch you and i lost my interest.

  • @pradeepkumarreddykondreddy7048
    @pradeepkumarreddykondreddy7048 5 років тому

    this guy is too fast

    • @RameshK-dy6yb
      @RameshK-dy6yb 4 роки тому

      for simple basics ua-cam.com/video/x2QOzdh0Fqs/v-deo.html

  • @aaaab384
    @aaaab384 5 років тому

    If you have such a thick accent, consider SLOWING DOWN A LOT.

  • @einfacherkerl3279
    @einfacherkerl3279 5 років тому

    his talking style is very...... weird