what is the use of AtomicInteger inside lock

In this section from java.util.concurrent.LinkedBlockingQueue.put() method, I think there is no need of AtomicInteger. Considering there is only one thread inside lock(). Am I correct?

putLock.lockInterruptibly();
    try {
        while (count.get() == capacity) {
            notFull.await();
        }
        enqueue(node);
        c = count.getAndIncrement();
        if (c + 1 < capacity)
            notFull.signal();
    } finally {
        putLock.unlock();
    }

I checked many questions, but can not find answer. My question: there is only one thread inside lock, so why to use AtomicInteger here