A modern programming language that makes developers happier.

kotlinlang

*Couroutines lets you do the asynchronous work in Non Blocking thread way*

I used three *launch{}* with delay (200) in UI thread Only . 
So Can I say it's like Time division in UI thread .
Like when first launch {} is delay(200) , then UI thread becomes Idle and second launch {} begins to execute then .

Please correct me if wrong ?

Could you show code, do you mean you have delay inside of your coroutine or between launch runs?

in all this cases delay is not blocking, so all launch will start and finish almost at the same time.

delay for Main dispatcher implemented on top of non-blocking delay, so this delay doesn’t block any thread

You can easily check it yourself:
<https://pl.kotl.in/BJN3KNX-V>

So returning to your question, there is some scheduling on thread (what you call “time division”), but there  is no thread blocking, so each launch run in parallel, because no blocking operations involved

Yeah I got that no blocking is involved 
But is the flow of operations is like this 
1)Delay() is also suspending function. So it suspends. Make the thread in idle state. 
2) Now thread is in idle state second launch{}  will run  
?


&gt; Make the thread in idle state
It’s wrong

For example in case of delay()  implementation for Android Main dispatcher will be started new Handler with delay, this managed by message queue of handler, so no thread switching, no thread idle. coroutine just subscribed on callback and return from suspend state when callback will be called

Ok So under the hood only CallBack is involved in MY CASE .
But still all the tasks happen parallel .?

Because `delay` does nothing, so delay operation started and event queue just spin it until delay finished. If you intereseted how it implemented, check Android Looper implementation or `runBlocking` event queue in kotlinx.coroutines, it’s universal approach, used a lot for async operations on single-threaded environment, for example in JS

Great :grinning: . I just knew from the surface the working of looper . 
I will check deeply then 