import org.apache.cassandra.config.RequestSchedulerOptions; //导入依赖的package包/类
public RoundRobinScheduler(RequestSchedulerOptions options)
{
    defaultWeight = options.default_weight;
    weights = options.weights;

    // the task count is acquired for the first time _after_ releasing a thread, so we pre-decrement
    taskCount = new Semaphore(options.throttle_limit - 1);

    queues = new NonBlockingHashMap<String, WeightedQueue>();
    Runnable runnable = new Runnable()
    {
        public void run()
        {
            while (true)
            {
                schedule();
            }
        }
    };
    Thread scheduler = new Thread(runnable, "REQUEST-SCHEDULER");
    scheduler.start();
    logger.info("Started the RoundRobin Request Scheduler");
}
 

import org.apache.cassandra.config.RequestSchedulerOptions; //导入依赖的package包/类
public RoundRobinScheduler(RequestSchedulerOptions options)
{
    assert !started;

    defaultWeight = options.default_weight;
    weights = options.weights;

    taskCount = new Semaphore(options.throttle_limit);
    queues = new NonBlockingHashMap<String, Pair<Integer, SynchronousQueue<Thread>>>();
    Runnable runnable = new Runnable()
    {
        public void run()
        {
            while (true)
            {
                schedule();
            }
        }
    };
    Thread scheduler = new Thread(runnable, "REQUEST-SCHEDULER");
    scheduler.start();
    logger.info("Started the RoundRobin Request Scheduler");
    started = true;
}
 

import org.apache.cassandra.config.RequestSchedulerOptions; //导入依赖的package包/类
public NoScheduler(RequestSchedulerOptions options) {}