schedule-task.scala

  import monix.eval.Task
  import monix.execution.Scheduler
  import scala.util.control.NonFatal

  /** Evaluates the given non-strict value on a given
    * `Scheduler`, meant for expensive I/O.
    *
    * NOTE: the returned task is not cancelable. In this
    * instance you wouldn't gain anything by it.
    */
  def executeIO[A](ioScheduler: Scheduler)(f: => A): Task[A] =
    Task.unsafeCreate { (scheduler, conn, callback) =>
      // Schedule for execution on the given thread!
      ioScheduler.execute(new Runnable {
        def run(): Unit = {
          var signalErrors = true
          try {
            val result = f
            signalErrors = false
            callback.onSuccess(result)
          } catch {
            case NonFatal(ex) =>
              if (signalErrors) callback.onError(ex)
              else scheduler.reportFailure(ex)
          }
        }
      })
    }