浅谈JDK BlockingQueue的实现类之ArrayBlockingQueue

    ArrayBlockingQueue实现了java.util.concurrent.BlockingQueue接口,是一个基于数组实现的一个阻塞队列,在该类里面常用到put(E e)和take()方法.

   put(E e):该方法表示存入一个元素到阻塞队列里去,如果队列已满,则进行等待

public void put(E e) throws InterruptedException {
        if (e == null) throw new NullPointerException();
        final E[] items = this.items;
        final ReentrantLock lock = this.lock;
        lock.lockInterruptibly();
        try {
            try {
                while (count == items.length)
                    notFull.await();
            } catch (InterruptedException ie) {
                notFull.signal(); // propagate to non-interrupted thread
                throw ie;
            }
            insert(e);
        } finally {
            lock.unlock();
        }
    }

 private void insert(E x) {
        items[putIndex] = x;
        putIndex = inc(putIndex);
        ++count;
        notEmpty.signal();
    }

 take():该方法表示从一个阻塞队列里取出元素，如果阻塞队列为空,则进行等待

 public E take() throws InterruptedException {
        final ReentrantLock lock = this.lock;
        lock.lockInterruptibly();
        try {
            try {
                while (count == 0)
                    notEmpty.await();
            } catch (InterruptedException ie) {
                notEmpty.signal(); // propagate to non-interrupted thread
                throw ie;
            }
            E x = extract();
            return x;
        } finally {
            lock.unlock();
        }
    }

 private E extract() {
        final E[] items = this.items;
        E x = items[takeIndex];
        items[takeIndex] = null;
        takeIndex = inc(takeIndex);
        --count;
        notFull.signal();
        return x;
    }