51,397
社区成员




private int num = 0;
public synchronized void add(int i){
num += i;
}
public synchronized void dec(int i){
num += i;
}
private AtomicInteger num = new AtomicInteger(0);
public void add(int i){
num.addAndGet(i);
}
public void dec(int i){
num.addAndGet(-i);
}