Concurrency

1188. Design Bounded Blocking Queue

    Deque<Integer> d;
    int size;
    Object lock;
    public BoundedBlockingQueue(int capacity) {
        d = new LinkedList<>();
        size = capacity;
        lock = new Object();
    }
    
    public void enqueue(int element) throws InterruptedException {
        synchronized (lock) {
            while (d.size() == size) {
                lock.wait();
            }
            d.addLast(element);
            lock.notify();
        }
    }
    
    public int dequeue() throws InterruptedException {
        int val = 0;
        synchronized (lock) {
            while (d.isEmpty()) lock.wait();
            val = d.removeFirst();
            lock.notify();
        }
        return val;
    }
    
    public int size() {
        return d.size();
    }