# DelayQueue

**Repository Path**: zclget/delay-queue

## Basic Information

- **Project Name**: DelayQueue
- **Description**: 简介：
DelayQueue是一个无界阻塞队列，只有在延迟期满时，才能从中提取元素。
队列的头部，是延迟期满后保存时间最长的delay元素。
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-06-25
- **Last Updated**: 2021-06-25

## Categories & Tags

**Categories**: Uncategorized

**Tags**: queue

## README

# DelayQueue
1. Order实现Delayed类
2. 重写getDelay和compareTo方法
3. new Thread执行
4. 源码解析
```java
public E take() throws InterruptedException {
        final ReentrantLock lock = this.lock;
        lock.lockInterruptibly();
        try {
            for (;;) {
                E first = q.peek();
                if (first == null)
                    available.await();
                else {
                    // 获取自实现的getDelay延迟时间
                    long delay = first.getDelay(NANOSECONDS);
                    if (delay <= 0)
                        return q.poll();
                    first = null; // don't retain ref while waiting
                    if (leader != null)
                        available.await();
                    else {
                        Thread thisThread = Thread.currentThread();
                        leader = thisThread;
                        try {
                            // 等待
                            available.awaitNanos(delay);
                        } finally {
                            if (leader == thisThread)
                                leader = null;
                        }
                    }
                }
            }
        } finally {
            if (leader == null && q.peek() != null)
                available.signal();
            lock.unlock();
        }
    }
```