Java 类之间的共享条件抛出 IllegalMonitorStateException：null

Question

我有这样的结构：
锁包装器 - 用于存储锁、条件和来自响应的对象

public class LockWrapper{
    private Lock lock;
    private Condition myCondition;
    private MyObject myObject;

    public LockWrapper(Lock lock, Condition myCondition) {
        this.lock = lock;
        this.myCondition = myCondition;
    }

    public Condition getMyCondition() {
        return myCondition;
    }

    public MyObject getMyObject() {
        return myObject;
    }

    public void setObject(MyObject myObject) {
        this.myObject = myObject;
    }

    public Lock getLock() {
        return lock;
    }

}

任务 - 推入线程池执行。它向服务器发起请求，然后等待服务器响应。

public class MyTask implements Runnable{
    private Lock lock = new ReentrantLock();
    private Condition myCondition = lock.newCondition();
    private MyWebSocketAPI api;

    public MyTask(MyWebSocketAPI api) {
         this.api = api;
    }

    @Override
    public void run() {
         lock.lock();
         try {
              // long randomLong = generateRandomLong();
              api.sendRequest(randomLong, new LockWrapper(lock, myCondition));
              myCondition.await();
              //do something after we got a response
         } finally{
              lock.unlock();
         }
    }

}

WebSocket - 获取请求并通知有关响应的任务

 public abstract class MyWebSocketAPI extends WebSocketClient {
    //...
    private Map<Long, LockWrapper> lockWrappers = new ConcurrentHashMap<>();

    public void sendRequest(Long id, LockWrapper lockWrapper){
        this.lockWrappers.put(id, lockWrapper);
        //processRequest
    }

    @Override
    public void onMessage(String message) {
        LockWrapper lockWrapper = lockWrappers.get(message.get(0).getAsLong());

        lockWrapper.getLock().lock();
        try{
            lockWrapper.setMyObject(new MyObject(message));
            this.lockWrappers.put(message.get(0).getAsLong(), lockWrapper);
            lockWrapper.getMyCondition().signalAll();
        } finally {
            lockWrapper.getLock().unlock();
        }
    }

    //...
 }

第 lockWrapper.getMyCondition().signalAll(); 行抛出异常：

java.lang.IllegalMonitorStateException: null
    at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.signalAll(AbstractQueuedSynchronizer.java:1954)

为什么当我试图通知任务我们得到了它们的对象时我的条件会抛出这个异常？是我哪里弄错了还是Java不允许共享条件？

Answer 1

这是我在 Task 中的错误。问题是我在方法运行中创建了全局和局部的 Lock 和 Condition。锁和条件具有相同的名称。在某些情况下，我使用 lock，在某些情况下，我使用 this.lock（但这是两个不同的锁）。结果，在方法 onMessage 中，我的 Condition 和 Lock 没有连接在一起。在我删除重复项后一切正常。

Java 类之间的共享条件抛出 IllegalMonitorStateException：null

Java shared condition between classes throws IllegalMonitorStateException: null

java

concurrency

multithreading

locking

java.util.concurrent

Java 类 之间的共享条件抛出 IllegalMonitorStateException：null

Java shared condition between classes throws IllegalMonitorStateException: null

java

concurrency

multithreading

locking

java.util.concurrent

Java 类之间的共享条件抛出 IllegalMonitorStateException：null