为什么ReentrantLock在SpringXD中不起作用

时间:2016-06-30 09:53:33

标签: java multithreading java.util.concurrent spring-xd

我正在尝试在SpringXD的工作中添加ReentrantLock,但有时似乎跨线程中断了。

例如,我有这些代码:

public class LoadGenerator extends MessageProducerSupport {

private final AtomicBoolean running = new AtomicBoolean(false);
private ExecutorService executorService;

Logger logger = LoggerFactory.getLogger(LoadGenerator.class);

public LoadGenerator(){}

@Override
protected void doStart() {
    executorService = Executors.newFixedThreadPool(2);
    if (running.compareAndSet(false, true)) {
        for (int x = 0; x < 10; x++) {
            executorService.submit(new Producer(Integer.toString(x)));
        }
    }
}

@Override
protected void doStop() {
    if (running.compareAndSet(true, false)) {
        executorService.shutdown();
    }
}

protected class Producer implements Runnable {
    String prefix;
    Lock lock = new ReentrantLock();

    public Producer(String prefix) {
        this.prefix = prefix;
    }

    private void send() {
        lock.lock();
        try{
            for(int i = 0; i < 10; i++){
                System.out.println(Thread.currentThread().getName() + " " + i);
            }
        }finally{
            lock.unlock();
        }
    }

    public void run() {
        send();
    }
}
}

我对它的期望是一个像

这样的列表
pool-604-thread-1 0
pool-604-thread-1 1
pool-604-thread-1 2
pool-604-thread-1 3
pool-604-thread-1 4
pool-604-thread-1 5
pool-604-thread-1 6
pool-604-thread-1 7
pool-604-thread-1 8
pool-604-thread-1 9
pool-604-thread-2 0
pool-604-thread-2 1
pool-604-thread-2 2
pool-604-thread-2 3
pool-604-thread-2 4
pool-604-thread-2 5
pool-604-thread-2 6
pool-604-thread-2 7
pool-604-thread-2 8
pool-604-thread-2 9
...

每个线程中的顺序和顺序不应该被中断,但事实是有时会出现中断:

pool-604-thread-1 0
pool-604-thread-2 0
pool-604-thread-2 1
pool-604-thread-2 2
pool-604-thread-1 1
pool-604-thread-1 2
pool-604-thread-1 3

有什么问题?这个锁在Eclipse上的localhost上运行良好,经过测试。

是因为SpringXD是分布式系统吗?但我只有一个xdcontaier连接到我的xdadmin。

感谢。

1 个答案:

答案 0 :(得分:3)

您应该通过ReentrantLock而不是在每个新Runnable中创建它,制作者应该共享一个ReentrantLock,例如:

@Override
protected void doStart() {
    executorService = Executors.newFixedThreadPool(2);
    Lock lock = new ReentrantLock();   // create a share lock to lock in multi threads
    if (running.compareAndSet(false, true)) {
        for (int x = 0; x < 10; x++) {
            executorService.submit(new Producer(Integer.toString(x), lock)); //pass this lock to every producer
        }
    }
}
protected class Producer implements Runnable {
    String prefix;
    final Lock lock;

    public Producer(String prefix, Lock lock) {
        this.prefix = prefix;
        this.lock = lock;
    }

    private void send() {
        lock.lock();
        try{
            for(int i = 0; i < 10; i++){
                System.out.println(Thread.currentThread().getName() + " " + i);
            }
        }finally{
            lock.unlock();
        }
    }

    public void run() {
        send();
    }
}