Question Should not `runBlocking Dispatchers Main ` be the s kotlinlang #coroutines

Question: Should not `runBlocking(Dispatchers.Main...

JoakimForslund

09/27/2019, 10:06 AM

Question: Should not

runBlocking(Dispatchers.Main) {}

be the same as running

Handler(Looper.getMainLooper()).post{}

on android?

gildor

09/27/2019, 10:09 AM

~~Yes, it’s pretty close, Dispatchers.Main on Android uses Handler with main looper to dispatch coroutines~~ UPD: just now realized that you use runBlocking, no, it’s not the same, because it’s blocking

JoakimForslund

09/27/2019, 10:13 AM

I'm curious, because it does not seem to translate well when trying to for instance, for a webview javascript bridge, force the call to run on main thread. I can run and force the thread (without issues)

Copy code

@JavascriptInterface
        override fun back() {
            Handler(Looper.getMainLooper()).post {
                this@PlatformSpecific.back()
            }
        }

But running this:

Copy code

@JavascriptInterface
        override fun back() {
            runBlocking(Dispatchers.Main) {
                this@PlatformSpecific.back()
            }
        }

Seems to lock the thread switch entirly

gildor

09/27/2019, 10:16 AM

Ohhh,

gildor

09/27/2019, 10:16 AM

sorry, I just now got what you are doing

gildor

09/27/2019, 10:17 AM

No, it;’s not the same

gildor

09/27/2019, 10:17 AM

do not use runBlocking for this, it will block the thread

gildor

09/27/2019, 10:17 AM

use

launch(Dispatchers.Main)

instead

JoakimForslund

09/27/2019, 10:18 AM

Oh yeah.. I'm a retard you are of course correct. I'm not trying to run a blocking action at all..

gildor

09/27/2019, 10:22 AM

Yeah, I just also was a bit confused by not-common combination of runBlocking and async handler in your question

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