Updated coroutines to 0.30.0 and removed (most of) deprecated code

[gmariotti]

• CoroutineVerticle implements now CoroutineScope based on Change default for global vs child coroutines by scoping coroutine builder (structured concurrency) Kotlin/kotlinx.coroutines#410
• Used GlobalScope.launch over launch when a verticle doesn't exist.
• Renamed tests for improving readability.
• Reverted to coroutines 0.30.0 to avoid warnings from atomicfu-common:0.11.10 that uses kotlin-stdlib-common:1.3.0-rc-131.

Next steps:

• Adjust documentation for coroutines module. (how should I update the examples in index.adoc?)
• Remove deprecated ArrayChannel in ReceiveChannelHandler.
• Make project depend on Kotlin 1.3.x and support the latest coroutines version.

[vietj]

can you make sure that the stdlib used by coroutines is the same than the globally declared stdlib ?

[vietj]

what is the interest to implement CoroutineScope for the CoroutineVerticle ?

[gmariotti]

what is the interest to implement CoroutineScope for the CoroutineVerticle ?

Not an expert here, but my understanding is that CoroutineScope should be implemented by entities that have a defined lifecycle, like a Verticle, and that will start child coroutines, making each coroutine bounded to the parent scope by default, potentially avoiding memory leaks. @elizarov had an amazing talk at KotlinConf this year and he can definitely explain it better than me.

[vietj]

@gmariotti makes sense, I think this should be documented in the coroutine verticle and in the general documentation

[gmariotti]

@vietj Updated the documentation of CoroutineVerticle. I was thinking of opening a new PR, after the one for ReceiveChannelHandler, to update the documentation for vertx-lang-kotlin-coroutines, is that ok? Also, is there any maven command to copy the examples to index.adoc or do they need to be manually copied?

[vietj]

I think if we document this, it should be in this PR.

for the docs : I think the current doc is wrong, it should contain asciidoc references that will copy the code as far as I remember, like explained in this blog : http://mrhaki.blogspot.com/2014/04/awesome-asciidoc-include-partial-parts.html . I think we need first a PR that fixes that.

[gmariotti]

@vietj opened #84, but I'll need some help to better understand how the docs should be generated.

[vietj]

I'm going to take care of that for you

[vietj]

@gmariotti please use https://github.com/vert-x3/vertx-lang-kotlin/tree/gmariotti-asciidoc which is based on this PR, it provides the necessary hooks to use inclusion and preview (documented in README.adoc)

[gmariotti]

@vietj should we merge your branch first and then I'll rebase this branch and adjust the documentation?

[vietj]

is the branch ready to be merged ? if yes, we can merge it as it serves a single purpose

[gmariotti]

yes, I already took care of having all the examples in Example.kt

[gmariotti]

I'll close #84, considering that there's already https://github.com/vert-x3/vertx-lang-kotlin/tree/gmariotti-asciidoc

[vietj]

what's the status of this PR ?

[gmariotti]

@vietj sorry I didn't have time the last 2 days to update the documentation for the coroutines module. If it's fine for you, I'll try to do it before the end of the week

[vietj]

it's fine @gmariotti

[gmariotti]

@vietj documentation updated, let me know if there's something I should fix.

[vietj]

thanks for the contribution @gmariotti

[vietj]

I think we need also to document the new Async coroutine method in 3.6.0