# V6126\. Native synchronization used on high\-level concurrency class\.

The analyzer has detected that a subclass of java\.util\.concurrent\.locks\.Lock, java\.util\.concurrent\.locks\.Condition, java\.util\.concurrent\.locks\.ReadWriteLock, and/or java\.util\.concurrent\.locks\.StampedLock is passed to the synchronized statement\.

These classes belong to the category of high\-level concurrency classes, and their use with `synchronized` is incorrect\. Instead, it is recommended to use the locking mechanisms provided directly by these classes\.

When `synchronized` is used with such objects, it creates two independent synchronization systems\. One system is based on the object monitor \(via `synchronized`\), and the other is based on the internal locking mechanism of the class\. This can lead to the following issues:

* broken synchronization integrity;
* race conditions;
* deadlocks;
* unexpected program behavior\.

The incorrect code:

```cpp
Lock lock = new ReentrantLock();

synchronized(lock) {
    ....
}
```

The fixed code:

```cpp
Lock lock = new ReentrantLock();

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