sonarqube - 当前线程不是锁的所有者!淡褐色

Question

我有一个 Spring boot 应用程序，其中包含用于缓存的 Hazelcast。 当多个实例与 Hazelcast 集群时，我在解锁操作中遇到此异常:

java.lang.IllegalMonitorStateException: Current thread is not owner of the lock! -> Owner: 33ce48f8-dda3-471f-abae-994d25dcc030, thread ID: 55
    at com.hazelcast.concurrent.lock.operations.UnlockOperation.unlock(UnlockOperation.java:75) ~[hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.concurrent.lock.operations.UnlockOperation.run(UnlockOperation.java:64) ~[hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.Operation.call(Operation.java:170) ~[hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.impl.operationservice.impl.OperationRunnerImpl.call(OperationRunnerImpl.java:208) [hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.impl.operationservice.impl.OperationRunnerImpl.run(OperationRunnerImpl.java:197) [hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.impl.operationservice.impl.OperationRunnerImpl.run(OperationRunnerImpl.java:413) [hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.impl.operationexecutor.impl.OperationThread.process(OperationThread.java:153) [hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.impl.operationexecutor.impl.OperationThread.process(OperationThread.java:123) [hazelcast-3.11.4.jar!/:3.11.4]
    at com.hazelcast.spi.impl.operationexecutor.impl.OperationThread.run(OperationThread.java:110) [hazelcast-3.11.4.jar!/:3.11.4]

这是我执行锁定和解锁操作的组件:

package com.companyname.service.servicename.job;
import com.hazelcast.core.ILock;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class UpdateRaceCacheJob {

    @Scheduled(fixedDelay = 10000)
    public void updateRaceCache() {
        ILock lock = hazelcastInstance.getLock("race-lock");
        try {
            if (!lock.tryLock()) {
                return;
            }

            // service calls

        } finally {
            lock.unlock();
        }
    }
}

当我将 lock.unlock(); 行替换为:

if (lock.isLockedByCurrentThread()) {
    lock.unlock();    
}

我收到来自 Sonar 的警告: 沿着这个方法的所有执行路径解锁这个锁。

谢谢!

Answer 1

由于 Hazelcast 锁是分布式的，它们受到线程所有权的保护，因此只有锁定它的线程才能解锁。

在您的代码中，您使用了可能返回false 的tryLock。但是，finally block 在任何情况下都会执行解锁操作。因此，每次您无法获得锁(因为它被集群中的某个其他线程锁定)时，您将尝试解锁它并且您将获得该异常。

最好使用 lock.isLockedByCurrentThread() 检查所有权。