public void submitTaskToReadyQueue(DriverTask task) {
    task.lock();
    try {
      if (task.getStatus() != DriverTaskStatus.READY) {
        return;
      }
      readyQueue.push(task);
      task.setLastEnterReadyQueueTime(System.nanoTime());
    } finally {
      task.unlock();
    }
  }
The manager of fragment instances scheduling.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/schedule/DriverScheduler.java