Coroutine Actors and thread-safety

fvasco · March 5, 2017, 9:42pm

I’m writing some code for a local conference about Kotlin and Vert.x integration.
Maybe it is possible to switch from callback hell to actor style, i wrote some code about this.
This is the reference:

github.com

fvasco/vertKtDemo/blob/5c4a3ae52402fdc16ecb871be463032cac3639e9/src/main/kotlin/Verticle4.kt#L23


      
                          val workMessage = handle <String> { doWork(WorkStep.STEP4, description, vertx, it) }
                          eventBus.send(WorkStep.STEP5.busName, workMessage)
                      }
                  }
              }
          }
          
          
suspend fun <T> ReadStream<T>.forEach(block: suspend (T) -> Unit) {
              suspendCoroutine <Unit> { cont: Continuation<Unit> ->
                  handler { handler ->
                      pause()
                      launchFuture {
                          block(handler)
                      }.setHandler { asyncResult ->
                          if (asyncResult.succeeded()) {
                              resume()
                          } else {
                              // remove handler
                              handler(null)
                              cont.resumeWithException(asyncResult.cause())
                          }

Because the actor must elaborate messages sequentially, I managed backpressure of Vertx ReadStream: when a new message arrives the stream is paused, after message elaboration the stream is resumed.
The concurrency is around the actors, not inside the actors.

Disclaimer: the code isn’t fully working and it is designed only for demostrative purpose. Please share your feedback about it. Thank you.

Topic		Replies	Views
Mutable state defined inside or outside coroutines - does it matter? Support	10	2290	April 10, 2020
Flows and mutable state Support	11	2784	August 26, 2020
Pls help me creating my first Actor Support	4	2813	October 6, 2019
Coroutine Actor obsolete Support	1	3461	July 30, 2019
Suspend-safety - something to keep in mind Libraries	7	4099	March 19, 2021

Coroutine Actors and thread-safety

Related topics