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.
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 CZcams, this requires exceptional skills. Not just coding but presence of mind.
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.
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!
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?
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!!!!!
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.
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
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
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 ?
Před 5 lety+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
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.
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.
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.
"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
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?
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 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.
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.
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.
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.
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
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.
This guy is who made me start kotlin, greet to see him in the Kotlin Conf
same here man
I read his programming kotlin
I've not seen anyone explaining the internals of coroutines better than Venkat Subramaniam.
czcams.com/video/YrrUCSi72E8/video.html
he is the best speaker I have seen so far.
no 1 can do that :)
That's some introduction. I like how he explained the "Why?" part of the changes.
I'm a simple man. I see Venkat Subramariam in a video title, I click.
Venkat and/or Florina on the title is enough to make me suspend all I'm doing and click on the video.
To click is to do the needful
It's so true
Same here.. even if I've watched it before, it's so satisfying
@@chukzydee suspend, you're saying, I see what you did here...
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 CZcams, this requires exceptional skills. Not just coding but presence of mind.
What a god damn pro, sometimes I need to pause to think about what he said
The buffering does that for me
I love Venkat voice, it is so calming.
I refer to Venkat's lectures whenever I get to the mood of seeking out wisdom 😌
One of the best talks I've watched in a long time.
really like a way he explains stuff, his talk about DSLs also nice
What a legend. Solved so many queries I had about coroutines with such simple but precise and amazing explanations.
He explains it so well and so simply. A very bright man.
This guys speech is so captivating!
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.
Amazing talk. Impressed by his coding and explanation going hand in hand.
Good examples. the multitasking while presentation using vim is incredible. !! Also the sound of claps at end of video says it all.
I've never seen anyone program in VI before. It felt a bit like black magic.
That last example of step by step conversion from sequential -> suspend -> async did the trick for me :)
Amazing talk, thanks for the content!
Excellent stuff, Venkat. Great explanations and witty humor.
He is really awesome. He is totally different from any other devs. It's like an entertainer or magician.
This talk was great. Thanks Venkat!
Just loved it. Thanks for this simple explanation
this was fantastic.
Every the venkat's videos make me to want to be a better developer 💪🏿. Great explanation!
amazing and so engaging.
The one and only.
We meet again.
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!
Loved it
the best speaker ever ) java versions are bumping, new langs come and go. but Venkat is a guy who always was with us )
thanks sir ,best lecture on coroutine
Great stuff!
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?
Отличная информация, спасибо большое!
excellent excellent excellent
Venkat Superman
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!!!!!
Great presentation, great teacher!
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.
Glad you liked it
Live coding! Awesome!
Amazing presentation
Thank you! Cheers!
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
Awesome. Much appreciated...👍🏾
Amazing talk, but I am curious what the setup is being used for interactive Kotlin/Java coding in vi/vim
Great great presentation. 🙌
Thank you kindly!
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
Venkat is such an awesome teacher
A very good explanation, thank you!
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 ?
Instead of suspend measureTime you could have made it inline, i think it would work with await 😀 really nice talk btw, finally understood coroutines
I think the goal of the talk was to show how suspend functions make a difference, and allow thread blocking versus non-suspension functions.
Frankly, found it quite convoluted
3:10 HOLY MAMA! WATTA HELL IS GOIN' ON? (Nice talk, by the way. Good job!)
@37:53 So this all is really just syntactic sugar for Thread pools and ComplteableFutures?
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.
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.
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.
Venkat is God of programming
VERY GOOD EXPLANATION...
yes
the " A sequential code" part is hard to understand :(
One of the best talk on coroutines (Y)
Which IDE is he using to show the demo?
"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
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?
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.
@@vyli1 so the call to launch() is indeed unnecessary?
@@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.
How is he auto-filling sentences ?
isnt this all wrong?slapping suspend on a blocking call doesnt not make it async, its just synchronous within dispatcher thread from launch
This guy literally looks like my maths professor.
Wow that was really good!! 😱😱 👏👏 just really wanna show my appreciation here 👏👏
Which editor does he use?
TextMate.
You have the last name of Venkat spelled wrong in the title
Thank you. Fixed.
👍
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.
what a killer mustache
Meu Deus, pare 1 segundo pra respirar!!!
is this man from pragimtech.com ?
No, we don't believe so. Dr. Venkat Subramaniam is the founder of Agile Developer, Inc. agiledeveloper.com
What do Coroutines offer that RxJava does not?
proandroiddev.com/kotlin-coroutines-vs-rxjava-an-initial-performance-test-68160cfc6723
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.
... although I must say - sequence continuations in Coroutines are super simple to reason about and much easier to teach to a newbie than RxJava
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.
I love rx, but flatmapping singles is stupid and you need to always return tuples everywhere like an idiot
He changed camps, first Scala, now this lol
He need pauses.
What is that, well, IDE?
That's a text editor. Probably TextMate.
I like the way it displays output at cursor.
@@jakubgwozdz2780 Yes, you have to configure. Long back after I saw his talk on Java Streams, I also configured like that. :)
Bm -16:58
TBH, Very hard to follow. Keep the sentences simple and the example simpler.
He is coding and explaining at the same time. He is so async.
27:00 Only moment, I can laugh.
28:30 suspend bytecode -> Continuation
this guy is too fast
for simple basics czcams.com/video/x2QOzdh0Fqs/video.html
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
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.
If you have such a thick accent, consider SLOWING DOWN A LOT.
his talking style is very...... weird