对《从ReentrantLock的实现看AQS的原理及应用》文章内容的疑问

final boolean nonfairTryAcquire(int acquires) {
	final Thread current = Thread.currentThread();
	int c = getState();
	if (c == 0) {
	    if (compareAndSetState(0, acquires)) {
	        setExclusiveOwnerThread(current);
	        return true;
	    }
	}
	else if (current == getExclusiveOwnerThread()) {
	    int nextc = c + acquires;
	    if (nextc < 0) // overflow
	        throw new Error("Maximum lock count exceeded");
	    setState(nextc);
	    return true;
	}
	return false;
}