Queue.ArrayBlockQueue

#ArrayBlockQueue

• 見名知義，數組結構，阻塞隊列，線程安全
• 內部結構

//存儲數組
    final Object[] items;
    //取索引
    int takeIndex;
    //插索引
    int putIndex;
    //元素容量
    int count;
    //同步鎖
    final ReentrantLock lock;
    //取阻塞條件
    private final Condition notEmpty;
    //插入阻塞條件
    private final Condition notFull;

• put 方法，插入，滿則等待

//lock 優先考慮獲取鎖，待獲取鎖成功後，才響應中斷。
//lockInterruptibly 優先考慮響應中斷，而不是響應鎖的普通獲取或重入獲取
public void put(E e) throws InterruptedException {
        checkNotNull(e);
        final ReentrantLock lock = this.lock;
        //容許其餘線程來來中斷當前線程，拋出異常
        lock.lockInterruptibly();
        try {
            while (count == items.length)
                notFull.await();
            enqueue(e);
        } finally {
            lock.unlock();
        }
    }

public E take() throws InterruptedException {
        final ReentrantLock lock = this.lock;
        lock.lockInterruptibly();
        try {
            while (count == 0)
                notEmpty.await();
            return dequeue();
        } finally {
            lock.unlock();
        }
    }

• TODO 遍歷過程，同步，操做指針