private void doLoad() {
        for (final String loadTaskTrackerNodeGroup : LOAD_SIGNAL) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    AtomicBoolean loading = LOADING.get(loadTaskTrackerNodeGroup);
                    if (loading == null) {
                        loading = new AtomicBoolean(false);
                        AtomicBoolean _loading = LOADING.putIfAbsent(loadTaskTrackerNodeGroup, loading);
                        if (_loading != null) {
                            loading = _loading;
                        }
                    }
                    if (loading.compareAndSet(false, true)) {
                        try {
                            handleSignal(loadTaskTrackerNodeGroup);
                        } finally {
                            loading.compareAndSet(true, false);
                        }
                    }
                }
            }).start();
        }
    }
@author Robert HG (254963746@qq.com) on 8/14/15.
lts-core/src/main/java/com/github/ltsopensource/queue/AbstractPreLoader.java