LoggingScheduledThreadPoolExecutorV2.scala

class LoggingScheduledThreadPoolExecutor(nthreads: Int)
    extends ScheduledThreadPoolExecutor(nthreads) {

    private val log = Logger(LoggerFactory.getLogger(classOf[LoggingScheduledThreadPoolExecutor]))

    class CustomTask[T](runnable: AnyRef, task: RunnableScheduledFuture[T])
        extends RunnableScheduledFuture[T] {

        val creationTime = System.nanoTime()

        override def isCancelled: Boolean = task.isCancelled

        override def isPeriodic: Boolean = task.isPeriodic

        override def getDelay(unit: TimeUnit): Long = task.getDelay(unit)

        override def run(): Unit = {
            val startTime = System.nanoTime()
            val timeWaiting = (startTime - creationTime) / 1000000
            log debug s"Starting task $task after $timeWaiting ms in queue"
            task.run()
            val tookTime = (System.nanoTime() - startTime) / 1000000
            log debug s"Finished task $task took $tookTime ms"
        }

        override def compareTo(o: Delayed): Int = task.compareTo(o)

        override def get(): T = task.get()

        override def get(timeout: Long,
                         unit: TimeUnit): T = task.get(timeout,unit)

        override def cancel(mayInterruptIfRunning: Boolean): Boolean = task.cancel(mayInterruptIfRunning)

        override def isDone: Boolean = task.isDone
    }

    override def decorateTask[V](runnable: Runnable,
                                 task: RunnableScheduledFuture[V]): RunnableScheduledFuture[V] = {
        new CustomTask(runnable,task)
    }

    override def decorateTask[V](callable: Callable[V],
                                 task: RunnableScheduledFuture[V]): RunnableScheduledFuture[V] = {
        new CustomTask(callable,task)
    }
}