private void removeWorker() {
        synchronized (this.workers) {
            if (this.workers.size() <= super.getCorePoolSize()) {
                return;
            }
            this.waitingIoCatalogs.offer(EXIT_SIGNAL);
        }
    }
Add a new Worker only if there are no idle worker.
metamorphosis-server-wrapper/src/main/java/com/taobao/metamorphosis/gregor/slave/OrderedThreadPoolExecutor.java