redisson分布式锁中waittime的设置

之前分布式锁中使用redisson的lock.tryLock(0,0,TimeUnit.SECONDS)

这么做的逻辑是releaseTime设置为0，实际上会使用默认的30s并触发看门狗机制

那waitTime有没有默认值呢？设置为0实际会等待多少时间？

看源码

 public boolean tryLock(long waitTime, long leaseTime, TimeUnit unit) throws InterruptedException {
        long time = unit.toMillis(waitTime);
        long current = System.currentTimeMillis();
        long threadId = Thread.currentThread().getId();
        Long ttl = this.tryAcquire(waitTime, leaseTime, unit, threadId);
        if (ttl == null) {
            return true;
        } else {
            time -= System.currentTimeMillis() - current;
            if (time <= 0L) {
                this.acquireFailed(waitTime, unit, threadId);
                return false;
            } else {
            ........

这里的time直接就取的传入的waitTime，当time减少到小于0时，返回加锁失败！

所以waitTime是没有什么默认值的，这么写相当于加锁失败立刻返回

实验一下，先加一个不会过期的锁，然后另一个线程试图获取锁

@Test
    public void getLock() throws InterruptedException {
        String lockKey = "testLock";
        RLock lock = redissonClient.getLock(lockKey);
        System.out.println(System.currentTimeMillis());
        Boolean isLock = lock.tryLock(0,-1,TimeUnit.SECONDS);
        System.out.println(System.currentTimeMillis());
        System.out.println(isLock);
    }