阻塞queue系列之LinkedBlockingQueue

LinkedBlockingQueue继承AbstractQueue，实现了BlockingQueue，Serializable接口。内部使用单向链表存储数据。可定义容量，默认初始化容量是Integer最大值（可能出现内存溢出）。插入和取出使用不同的锁，putLock插入锁，takeLock取出锁，添加和删除数据的时候可以并行。多CPU情况下可以同一时刻既消费又生产。LinkedBlockingQueue在大多数并发的场景下吞吐量比ArrayBlockingQueue，但是性能不稳定。

private final ReentrantLock takeLock = new ReentrantLock();

    /** Wait queue for waiting takes */
    private final Condition notEmpty = takeLock.newCondition();

    /** Lock held by put, offer, etc */
    private final ReentrantLock putLock = new ReentrantLock();

    /** Wait queue for waiting puts */
    private final Condition notFull = putLock.newCondition();

构造函数

public LinkedBlockingQueue() {
        this(Integer.MAX_VALUE);
    }

public LinkedBlockingQueue(int capacity) {
        if (capacity <= 0) throw new IllegalArgumentException();
        this.capacity = capacity;
        last = head = new Node<E>(null);
    }

public LinkedBlockingQueue(Collection<? extends E> c) {
        this(Integer.MAX_VALUE);
        final ReentrantLock putLock = this.putLock;
        putLock.lock(); // Never contended, but necessary for visibility
        try {
            int n = 0;
            for (E e : c) {
                if (e == null)
                    throw new NullPointerException();
                if (n == capacity)
                    throw new IllegalStateException("Queue full");
                enqueue(new Node<E>(e));
                ++n;
            }
            count.set(n);
        } finally {
            putLock.unlock();
        }
    }

常用方法

常用方法与ArrayBlockingQueue类似，方法具体实现可以参考源码。