advanced patterns with Scala Futures and Custom ExecutionContext in Scala 2.13.5
I've been struggling with this for a few days now and could really use some help. I'm working with an scenario where my custom `ExecutionContext` is not handling the completion of `Future` as I expected... I created a custom `ExecutionContext` to control the threading model better, but it seems that some futures are completing with unexpected behaviors, leading to race conditions. Here's the snippet of my code where I define the `ExecutionContext` and use it: ```scala import scala.concurrent.{ExecutionContext, Future} import scala.util.{Failure, Success} object MyExecutionContext { implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(java.util.concurrent.Executors.newFixedThreadPool(4)) } object MyApp extends App { import MyExecutionContext._ def asyncOperation(id: Int): Future[Int] = Future { Thread.sleep(1000) id * 2 } val results = for { a <- asyncOperation(1) b <- asyncOperation(2) } yield a + b results.onComplete { case Success(value) => println(s"Result: $value") case Failure(e) => println(s"behavior: ${e.getMessage}") } } ``` When I'm running this, sometimes I get `Result: 6`, but other times I see an `behavior: Future already completed` message. I need to figure out why the future completes before the operations finish, especially since I expect both `asyncOperation` calls to run sequentially in this context. I've tried increasing the thread pool size and switching to a `ForkJoinPool`, but the question continues. Has anyone experienced similar behavior or can provide insights on how to handle this correctly? For context: I'm using Scala on Debian. What are your experiences with this? Hoping someone can shed some light on this. My team is using Scala for this REST API. I'm open to any suggestions. I'm coming from a different tech stack and learning Scala. What am I doing wrong?