Redis分布式锁如何实现续期

public class DemoMain {
    public static void main(String[] args) throws Exception {
        Config config = new Config();
        config.useSingleServer().setAddress("redis://127.0.0.1:6379");
        RedissonClient redisson = Redisson.create(config);
        RLock lock = redisson.getLock("anyLock");
        lock.lock();
        //lock.unlock();
    }
}

public class Config {	
	private long lockWatchdogTimeout = 30 * 1000;		
	public long getLockWatchdogTimeout() {
		return lockWatchdogTimeout;
	}	
	//省略无关代码
}

public void lock() {
    while (true) {
        boolean flag = this.getLock(key);
        if (flag) {
              TODO .........
        } else {
              // 释放当前redis连接
              redis.close();
              // 休眠1000毫秒
             sleep(1000);
       }
     }
 }

SETNX key value

 @Transaction
 public void lock() {
      while (true) {
          boolean flag = this.getLock(key);
          if (flag) {
              insert();
          }
      }
 }

  @Autowired
  DataSourceTransactionManager dataSourceTransactionManager;
  @Transaction
  public void lock() {
      //手动开启事务
      TransactionStatus transactionStatus = dataSourceTransactionManager.getTransaction(transactionDefinition);
      try {
          while (true) {
             boolean flag = this.getLock(key);
             if (flag) {
                 insert();
                 //手动提交事务
                 dataSourceTransactionManager.commit(transactionStatus);
             }
         }
     } catch (Exception e) {
         //手动回滚事务
         dataSourceTransactionManager.rollback(transactionStatus);
     }
 }

RLock lock = redissonClient.getLock("stockLock");

@Slf4j
@Service
public class RedisDistributionLockPlus {
   
   private static final long DEFAULT_LOCK_TIMEOUT = 30;
  private static final long TIME_SECONDS_FIVE = 5 ;
  
  private Map<String, LockContent> lockContentMap = new ConcurrentHashMap<>(512);
  
  private static final Long EXEC_SUCCESS = 1L;
  
  private static final String LOCK_SCRIPT = "if redis.call('exists', KEYS[2]) == 1 then ARGV[2] = math.floor(redis.call('get', KEYS[2]) + 10) end " +
          "if redis.call('exists', KEYS[1]) == 0 then " +
             "local t = redis.call('set', KEYS[1], ARGV[1], 'EX', ARGV[2]) " +
             "for k, v in pairs(t) do " +
               "if v == 'OK' then return tonumber(ARGV[2]) end " +
             "end " +
          "return 0 end";
  
  private static final String UNLOCK_SCRIPT = "if redis.call('get', KEYS[1]) == ARGV[1] then " +
          "local ctime = tonumber(ARGV[2]) " +
          "local biz_timeout = tonumber(ARGV[3]) " +
          "if ctime > 0 then  " +
             "if redis.call('exists', KEYS[2]) == 1 then " +
                 "local avg_time = redis.call('get', KEYS[2]) " +
                 "avg_time = (tonumber(avg_time) * 8 + ctime * 2)/10 " +
                 "if avg_time >= biz_timeout - 5 then redis.call('set', KEYS[2], avg_time, 'EX', 24*60*60) " +
                 "else redis.call('del', KEYS[2]) end " +
             "elseif ctime > biz_timeout -5 then redis.call('set', KEYS[2], ARGV[2], 'EX', 24*60*60) end " +
          "end " +
          "return redis.call('del', KEYS[1]) " +
          "else return 0 end";
  
  private static final String RENEW_SCRIPT = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('expire', KEYS[1], ARGV[2]) else return 0 end";
  private final StringRedisTemplate redisTemplate;
  public RedisDistributionLockPlus(StringRedisTemplate redisTemplate) {
      this.redisTemplate = redisTemplate;
      ScheduleTask task = new ScheduleTask(this, lockContentMap);
      // 启动定时任务
      ScheduleExecutor.schedule(task, 1, 1, TimeUnit.SECONDS);
  }
  
  public boolean lock(String lockKey, String requestId, long expire) {
      log.info("开始执行加锁, lockKey ={}, requestId={}", lockKey, requestId);
      for (; ; ) {
          // 判断是否已经有线程持有锁，减少redis的压力
          LockContent lockContentOld = lockContentMap.get(lockKey);
          boolean unLocked = null == lockContentOld;
          // 如果没有被锁，就获取锁
          if (unLocked) {
              long startTime = System.currentTimeMillis();
              // 计算超时时间
              long bizExpire = expire == 0L ? DEFAULT_LOCK_TIMEOUT : expire;
              String lockKeyRenew = lockKey + "_renew";
              RedisScript<Long> script = RedisScript.of(LOCK_SCRIPT, Long.class);
              List<String> keys = new ArrayList<>();
              keys.add(lockKey);
              keys.add(lockKeyRenew);
              Long lockExpire = redisTemplate.execute(script, keys, requestId, Long.toString(bizExpire));
              if (null != lockExpire && lockExpire > 0) {
                  // 将锁放入map
                  LockContent lockContent = new LockContent();
                  lockContent.setStartTime(startTime);
                  lockContent.setLockExpire(lockExpire);
                  lockContent.setExpireTime(startTime + lockExpire * 1000);
                  lockContent.setRequestId(requestId);
                  lockContent.setThread(Thread.currentThread());
                  lockContent.setBizExpire(bizExpire);
                 lockContent.setLockCount(1);
                 lockContentMap.put(lockKey, lockContent);
                 log.info("加锁成功, lockKey ={}, requestId={}", lockKey, requestId);
                 return true;
             }
         }
         // 重复获取锁，在线程池中由于线程复用，线程相等并不能确定是该线程的锁
         if (Thread.currentThread() == lockContentOld.getThread()
                   && requestId.equals(lockContentOld.getRequestId())){
             // 计数 +1
             lockContentOld.setLockCount(lockContentOld.getLockCount()+1);
             return true;
         }
         // 如果被锁或获取锁失败，则等待100毫秒
         try {
             TimeUnit.MILLISECONDS.sleep(100);
         } catch (InterruptedException e) {
             // 这里用lombok 有问题
             log.error("获取redis 锁失败, lockKey ={}, requestId={}", lockKey, requestId, e);
             return false;
         }
     }
 }
 
 public boolean unlock(String lockKey, String lockValue) {
     String lockKeyRenew = lockKey + "_renew";
     LockContent lockContent = lockContentMap.get(lockKey);
     long consumeTime;
     if (null == lockContent) {
         consumeTime = 0L;
     } else if (lockValue.equals(lockContent.getRequestId())) {
         int lockCount = lockContent.getLockCount();
         // 每次释放锁， 计数 -1，减到0时删除redis上的key
         if (--lockCount > 0) {
             lockContent.setLockCount(lockCount);
             return false;
         }
         consumeTime = (System.currentTimeMillis() - lockContent.getStartTime()) / 1000;
     } else {
         log.info("释放锁失败，不是自己的锁。");
         return false;
     }
     // 删除已完成key，先删除本地缓存，减少redis压力, 分布式锁，只有一个，所以这里不加锁
     lockContentMap.remove(lockKey);
     RedisScript<Long> script = RedisScript.of(UNLOCK_SCRIPT, Long.class);
     List<String> keys = new ArrayList<>();
     keys.add(lockKey);
     keys.add(lockKeyRenew);
     Long result = redisTemplate.execute(script, keys, lockValue, Long.toString(consumeTime),
             Long.toString(lockContent.getBizExpire()));
     return EXEC_SUCCESS.equals(result);
 }
 
 public boolean renew(String lockKey, LockContent lockContent) {
     // 检测执行业务线程的状态
     Thread.State state = lockContent.getThread().getState();
     if (Thread.State.TERMINATED == state) {
         log.info("执行业务的线程已终止,不再续约 lockKey ={}, lockContent={}", lockKey, lockContent);
         return false;
     }
     String requestId = lockContent.getRequestId();
     long timeOut = (lockContent.getExpireTime() - lockContent.getStartTime()) / 1000;
     RedisScript<Long> script = RedisScript.of(RENEW_SCRIPT, Long.class);
     List<String> keys = new ArrayList<>();
     keys.add(lockKey);
     Long result = redisTemplate.execute(script, keys, requestId, Long.toString(timeOut));
     log.info("续约结果，True成功，False失败 lockKey ={}, result={}", lockKey, EXEC_SUCCESS.equals(result));
     return EXEC_SUCCESS.equals(result);
 }
 static class ScheduleExecutor {
     public static void schedule(ScheduleTask task, long initialDelay, long period, TimeUnit unit) {
         long delay = unit.toMillis(initialDelay);
         long period_ = unit.toMillis(period);
         // 定时执行
         new Timer("Lock-Renew-Task").schedule(task, delay, period_);
     }
 }
 static class ScheduleTask extends TimerTask {
     private final RedisDistributionLockPlus redisDistributionLock;
     private final Map<String, LockContent> lockContentMap;
     public ScheduleTask(RedisDistributionLockPlus redisDistributionLock, Map<String, LockContent> lockContentMap) {
         this.redisDistributionLock = redisDistributionLock;
         this.lockContentMap = lockContentMap;
     }
     @Override
     public void run() {
         if (lockContentMap.isEmpty()) {
             return;
         }
         Set<Map.Entry<String, LockContent>> entries = lockContentMap.entrySet();
         for (Map.Entry<String, LockContent> entry : entries) {
             String lockKey = entry.geTKEy();
             LockContent lockContent = entry.getValue();
             long expireTime = lockContent.getExpireTime();
             // 减少线程池中任务数量
             if ((expireTime - System.currentTimeMillis())/ 1000 < TIME_SECONDS_FIVE) {
                 //线程池异步续约
                 ThreadPool.submit(() -> {
                     boolean renew = redisDistributionLock.renew(lockKey, lockContent);
                     if (renew) {
                         long expireTimeNew = lockContent.getStartTime() + (expireTime - lockContent.getStartTime()) * 2 - TIME_SECONDS_FIVE * 1000;
                         lockContent.setExpireTime(expireTimeNew);
                     } else {
                         // 续约失败，说明已经执行完 OR redis 出现问题
                         lockContentMap.remove(lockKey);
         
           }
                 });
             }
         }
     }
 }
}