Demo of concurrent, side-effecting operations in Scala with a configurable thread pool.

cio.scala

import scala.concurrent._
import scala.concurrent.duration._
import java.util.concurrent.Executors.newFixedThreadPool

val logger = java.util.logging.Logger.getLogger("par")
def f(n: Int): Int = {
  Thread.sleep(20000)
  logger.info(f"$n%04d")
  n*2
}

val e = newFixedThreadPool(8)
val ctx: ExecutionContext = ExecutionContext.fromExecutorService(e)
val futures = for (x <- 1 to 10) yield future(f(x))(ctx)
val res = futures.map(Await.result(_, 10.minute))