public void shutdown() {
        if (objectName != null) {
            JMXManager.tryUnregister(objectName);
            objectName = null;
        }

        if (executor != null) {
            executor.shutdown();
            executor = null;
        }

        if (timer != null) {
            timer.cancel();
            timer = null;
        }
    }
Shuts down the task engine service.
xmppserver/src/main/java/org/jivesoftware/util/TaskEngine.java