基于AQS自己实现一个同步器

package com.example.demo.Lock;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;

public class MyNonLock implements Lock, java.io.Serializable {
    
    //创建一个具体的MySync来做具体的工作
    private final MySync mySync = new MySync();

    @Override
    public void lock() {
        mySync.acquire(1);
    }

    @Override
    public boolean tryLock() {
        return mySync.tryAcquire(1);
    }
    
    @Override
    public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
        return mySync.tryAcquireNanos(1, unit.toNanos(time));
        
    }
    
    //带了Interruptibly的方法表示对中断进行响应，就是当一个线程在阻塞队列中被挂起的时候，
    //其他线程调用该线程的中断方法中断了该线程，该线程会抛出InterruptedException异常
    @Override
    public void lockInterruptibly() throws InterruptedException {
         mySync.acquireInterruptibly(1);
    }

    @Override
    public void unlock() {
        mySync.release(1);
    }

    //很方便的获取条件变量
    @Override
    public Condition newCondition() {
        return mySync.newCondition();
    }
    
    

    private static class MySync extends AbstractQueuedSynchronizer {

        // 锁是否已经被持有
        protected boolean isHeldExclusively() {
            return getState() == 1;
        }

        // 如果state为0，就尝试获取锁，将state修改为1
        public boolean tryAcquire(int acquires) {
            assert acquires == 1;
            if (compareAndSetState(0, 1)) {
                setExclusiveOwnerThread(Thread.currentThread());
                return true;
            }
            return false;
        }

        // 尝试释放锁，将state设置为0
        protected boolean tryRelease(int releases) {
            assert releases == 1;
            if (getState() == 0) {
                throw new IllegalMonitorStateException();
            }
            setExclusiveOwnerThread(null);
            setState(0);
            return true;
        }

        //提供条件变量接口
        Condition newCondition() {
            return new ConditionObject();
        }
    }

}

package com.example.demo.study;

import java.util.Queue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.locks.Condition;

import com.example.demo.Lock.MyNonLock;

public class Study0202 {
    // 我们往这个队列中添加字符串
    final static Queue<String> queue = new LinkedBlockingQueue<String>();
    // 创建我们自己的锁对象
    final static MyNonLock lock = new MyNonLock();
    // 当队列queue中字符串满了，其他的生产线程就丢到这个条件队列里面
    final static Condition full = lock.newCondition();
    // 当队列queue是空的，其余的消费线程就丢到这个条件队列里面
    final static Condition empty = lock.newCondition();
    // 队列queue中存字符串最多只能是3个
    final static int queue_MAX_SIZE = 3;

    //往队列queue中压入字符串
    public static void add() {
        lock.lock();
        try {
            // 当队列满了，就将其他生产线程丢进full的条件队列中
            while (queue.size() == queue_MAX_SIZE) {
                full.await();
            }
            System.out.println("prd:" + "hello");
            // 往队列queue中添加字符串
            queue.add("hello");
            // 生产成功，唤醒消费条件队列中的所有线程赶紧去消费
            empty.signalAll();
        } catch (Exception e) {
            //
        } finally {
            lock.unlock();
        }
    }

    //从队列queue弹出字符串
    public static void poll() {
        lock.lock();
        try {
            // 当队列queue中一个字符串都没有，就将剩下的消费线程丢进enpty对应的队列中
            while (queue.size() == 0) {
                empty.await();
            }
            // 消费队列queue中的字符串
            String poll = queue.poll();
            System.out.println("consumer:" + poll);
            // 消费成功，就唤醒full中所有的生产线程去生产字符串
            full.signalAll();
        } catch (Exception e) {
            //
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        // 生产者线程
        for (int i = 0; i < 5; i++) {
            new Thread(() -> {
                add();
            }).start();
        }

        // 消费者线程
        for (int i = 0; i < 5; i++) {
            new Thread(() -> {
                poll();
            }).start();
        }
    }
}