死锁获取锁定

Question

我有一个死锁的线程转储，我看不出原因。在第一次检查时，看起来某些客户端代码无法获取ReentrantLock所拥有的MyClass上的锁：

"qtp1450652220-77" Id=77 WAITING on java.util.concurrent.locks.ReentrantLock$NonfairSync@1e319fef owned by "pool-2-thread-2" Id=1651
    at sun.misc.Unsafe.park(Native Method)
    -  waiting on java.util.concurrent.locks.ReentrantLock$NonfairSync@1e319fef
    at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
    at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
    at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
    at com.mycode.MyClass.methodName(MyClass.java:1008)

然而，拥有线程的转储是：

"pool-2-thread-2" Id=1651 WAITING on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@56171f7a
    at sun.misc.Unsafe.park(Native Method)
    -  waiting on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@56171f7a
    at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
    at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
    at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

    Number of locked synchronizers = 1
    - java.util.concurrent.locks.ReentrantLock$NonfairSync@1e319fef

当然，ReentrantLock上的锁定列在底部。但令我惊讶的是，在线程转储中没有我的客户端代码。没有迹象表明ReentrantLock是如何被收购的，所以我该如何解决？

MyClass中的代码是：

public Collection<String> methodName() {

    interruptLock.lock();
    try {
        /* do stuff */
        return tagsToReturn;
    } finally {
        interruptLock.unlock();
    }
}

第1008行是interruptLock.lock();行。