java中linkedblockingqueue的增加方法

public void put(E e) throws InterruptedException {

        if (e == null) throw new NullPointerException();   //e不能为null

        int c = -1;

        Node<E> node = new Node<E>(e);

        final ReentrantLock putLock = this.putLock;     //获取put锁

        final AtomicInteger count = this.count;          //获取count

        putLock.lockInterruptibly();

        try {

            while (count.get() == capacity) {        //如果满了，那么就需要使用notFull阻塞

                notFull.await();

            }

            enqueue(node);

            c = count.getAndIncrement();

            if (c + 1 < capacity)                    //如果此时又有空间了，那么notFull唤醒

                notFull.signal();

        } finally {

            putLock.unlock();             //释放锁

        }

        if (c == 0)            //当c为0时候，也要根take锁说一下，并发下

            signalNotEmpty();        //调用notEmpty       

    }

public E take() throws InterruptedException {

    E x;

    int c = -1;

    final AtomicInteger count = this.count;

    final ReentrantLock takeLock = this.takeLock;

    // 使用takeLock加锁

    takeLock.lockInterruptibly();

    try {

        // 如果队列无元素，则阻塞在notEmpty条件上

        while (count.get() == 0) {

            notEmpty.await();

        }

        // 否则，出队

        x = dequeue();

        // 获取出队前队列的长度

        c = count.getAndDecrement();

        // 如果取之前队列长度大于1，则唤醒notEmpty

        if (c > 1)

            notEmpty.signal();

    } finally {

        // 释放锁

        takeLock.unlock();

    }

    // 如果取之前队列长度等于容量

    // 则唤醒notFull

    if (c == capacity)

        signalNotFull();

    return x;

}

private E dequeue() {

    // head节点本身是不存储任何元素的

    // 这里把head删除，并把head下一个节点作为新的值

    // 并把其值置空，返回原来的值

    Node<E> h = head;

    Node<E> first = h.next;

    h.next = h; // help GC

    head = first;

    E x = first.item;

    first.item = null;

    return x;

}

private void signalNotFull() {

    final ReentrantLock putLock = this.putLock;

    putLock.lock();

    try {

        // 唤醒notFull

        notFull.signal();

    } finally {

        putLock.unlock();

    }

}