重入锁的好搭档:Condition条件(读书笔记)

void await() throws InterruptedException;
void awaitUninterruptibly();
long awaitNanos(long nanosTimeout) throws InterruptedException;
boolean await(long time, TimeUnit unit) throws InterruptedException;
boolean awaitUntil(Date deadline) throws InterruptedException;
void signal();
void signalAll();

public class ReenterLockCondition implements Runnable {
    public static ReentrantLock lock = new ReentrantLock();
    public static Condition condition = lock.newCondition();

    /**
     * When an object implementing interface <code>Runnable</code> is used
     * to create a thread, starting the thread causes the object‘s
     * <code>run</code> method to be called in that separately executing
     * thread.
     * <p>
     * The general contract of the method <code>run</code> is that it may
     * take any action whatsoever.
     *
     * @see Thread#run()
     */
    @Override
    public void run() {
        try {
            lock.lock();
            condition.await();
            System.out.println("Thread is going on");
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        ReenterLockCondition r1 = new ReenterLockCondition();
        Thread t1 = new Thread(r1);
        t1.start();
        Thread.sleep(2000);
        lock.lock();
        condition.signal();
        lock.unlock();
    }
}

public void put(E e) throws InterruptedException {
    if (e == null) throw new NullPointerException();
    // Note: convention in all put/take/etc is to preset local var
    // holding count negative to indicate failure unless set.
    int c = -1;
    Node<E> node = new Node<E>(e);
    final ReentrantLock putLock = this.putLock;
    final AtomicInteger count = this.count;
    putLock.lockInterruptibly();//可以响应中断的锁 加锁
    try {
        /*
         * Note that count is used in wait guard even though it is
         * not protected by lock. This works because count can
         * only decrease at this point (all other puts are shut
         * out by lock), and we (or some other waiting put) are
         * signalled if it ever changes from capacity. Similarly
         * for all other uses of count in other wait guards.
         */
        while (count.get() == capacity) {//判断队列是否满了
            notFull.await();//等待
        }
        enqueue(node);//插入数据
        c = count.getAndIncrement();//更新总数,变量c是count加1前的值
        if (c + 1 < capacity)
            notFull.signal();//有足够的空间,通知其他线程
    } finally {
        putLock.unlock();//释放锁
    }
    if (c == 0)
        signalNotEmpty();//插入成功后,通知take操作去数据
}