reactor.addAll(InitMilestone.ordering().discoverTasks(reactor));
ExecutorService es;
if (Jenkins.PARALLEL_LOAD)
es = new ThreadPoolExecutor(
TWICE_CPU_NUM, TWICE_CPU_NUM, 5L, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(), new DaemonThreadFactory());
else
es = Executors.newSingleThreadExecutor(new DaemonThreadFactory());
try {
reactor.execute(es,buildReactorListener());
} finally {
es.shutdownNow(); // upon a successful return the executor queue should be empty. Upon an exception, we want to cancel all pending tasks
}