LeetCode（多线程）- 1188. 设计有限阻塞队列

class BoundedBlockingQueue {
    private final Queue queue;
    private final int size;
    private final ReentrantLock lock;
    private final Condition producer;
    private final Condition consumer;
    public BoundedBlockingQueue(int capacity) {
        size = capacity;
        queue = new LinkedList();
        lock = new ReentrantLock();
        producer = lock.newCondition();
        consumer = lock.newCondition();
    }
    public void enqueue(int element) throws InterruptedException {
        try {
            lock.lock();
            while (size() == size) {
                producer.await();
            }
            queue.add(element);
            consumer.signalAll();
        } finally {
            lock.unlock();
        }
    }
    public int dequeue() throws InterruptedException {
        try {
            lock.lock();
            while (queue.isEmpty()) {
                consumer.await();
            }
            int result = (int) queue.poll();
            producer.signalAll();
            return result;
        } finally {
            lock.unlock();
        }
    }
    public int size() {
        return queue.size();
    }
}