- 公平锁加锁的源码在RedissonFairLock
KEYS = Arrays.<Object>asList(getName(), threadsQueueName, timeoutSetName)
KEYS[1] = getName() = 锁的名字,“anyLock”
KEYS[2] = threadsQueueName = redisson_lock_queue:{anyLock},基于redis的数据结构实现的一个队列
KEYS[3] = timeoutSetName = redisson_lock_timeout:{anyLock},基于redis的数据结构实现的一个Set数据集合,有序集合,可以自动按照你给每个数据指定的一个分数(score)来进行排序
ARGV = internalLockLeaseTime, getLockName(threadId), currentTime + threadWaitTime, currentTime
ARGV[1] = 30000毫秒
ARGV[2] = UUID:threadId
ARGV[3] = 当前时间(10:00:00) + 5000毫秒 = 10:00:05
ARGV[4] = 当前时间(10:00:00)
代码片段一、
@Override
<T> RFuture<T> tryLockInnerAsync(long leaseTime, TimeUnit unit, long threadId, RedisStrictCommand<T> command) {
internalLockLeaseTime = unit.toMillis(leaseTime);
long currentTime = System.currentTimeMillis();
if (command == RedisCommands.EVAL_NULL_BOOLEAN) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, command,
// remove stale threads
"while true do "
+ "local firstThreadId2 = redis.call('lindex', KEYS[2], 0);"
+ "if firstThreadId2 == false then "
+ "break;"
+ "end; "
+ "local timeout = tonumber(redis.call('zscore', KEYS[3], firstThreadId2));"
+ "if timeout <= tonumber(ARGV[3]) then "
+ "redis.call('zrem', KEYS[3], firstThreadId2); "
+ "redis.call('lpop', KEYS[2]); "
+ "else "
+ "break;"
+ "end; "
+ "end;"
+
"if (redis.call('exists', KEYS[1]) == 0) and ((redis.call('exists', KEYS[2]) == 0) "
+ "or (redis.call('lindex', KEYS[2], 0) == ARGV[2])) then " +
"redis.call('lpop', KEYS[2]); " +
"redis.call('zrem', KEYS[3], ARGV[2]); " +
"redis.call('hset', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; " +
"if (redis.call('hexists', KEYS[1], ARGV[2]) == 1) then " +
"redis.call('hincrby', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; " +
"return 1;",
Arrays.<Object>asList(getName(), threadsQueueName, timeoutSetName),
internalLockLeaseTime, getLockName(threadId), currentTime);
}
if (command == RedisCommands.EVAL_LONG) {
return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTANCE, command,
// remove stale threads
// 1. 首先会进入到这里,lindex redisson_lock_queue:{anyLock} 0,获取队列中的第一个元素
"while true do "
+ "local firstThreadId2 = redis.call('lindex', KEYS[2], 0);”
+ "if firstThreadId2 == false then "
+ "break;"
+ "end; “
// 判断他的timeout时间是否大于当前时间,假设当前时间为10:00:08,不成立,直接跳出死循环
+ "local timeout = tonumber(redis.call('zscore', KEYS[3], firstThreadId2));"
+ "if timeout <= tonumber(ARGV[4]) then "
+ "redis.call('zrem', KEYS[3], firstThreadId2); "
+ "redis.call('lpop', KEYS[2]); "
+ "else "
+ "break;"
+ "end; "
+ "end;"
// 1. Exists anyLock,肯定是存在的,所以条件不成立
+ "if (redis.call('exists', KEYS[1]) == 0) and ((redis.call('exists', KEYS[2]) == 0) "
+ "or (redis.call('lindex', KEYS[2], 0) == ARGV[2])) then " +
"redis.call('lpop', KEYS[2]); " +
"redis.call('zrem', KEYS[3], ARGV[2]); " +
"redis.call('hset', KEYS[1], ARGV[2], 1); " +
"redis.call('pexpire', KEYS[1], ARGV[1]); " +
"return nil; " +
"end; “ +
// 1. Hexists anyLock UUID_01:thread_01 ,判断anyLock的hash中是否存在一个UUID_01:threadId_01的key,当前这个锁是否是客户端A加的锁,条件是成立的
"if (redis.call('hexists', KEYS[1], ARGV[2]) == 1) then “ +
// hincrby anyLock UUID_01:threadId_01 累加1
"redis.call('hincrby', KEYS[1], ARGV[2], 1); “ +
// 更新anyLock的生存周期为30000毫秒
"redis.call('pexpire', KEYS[1], ARGV[1]); “ +
// 返回nil
"return nil; " +
"end; " +
"local firstThreadId = redis.call('lindex', KEYS[2], 0); " +
"local ttl; " +
"if firstThreadId ~= false and firstThreadId ~= ARGV[2] then " +
"ttl = tonumber(redis.call('zscore', KEYS[3], firstThreadId)) - tonumber(ARGV[4]);" +
"else "
+ "ttl = redis.call('pttl', KEYS[1]);" +
"end; " +
"local timeout = ttl + tonumber(ARGV[3]);" +
"if redis.call('zadd', KEYS[3], timeout, ARGV[2]) == 1 then " +
"redis.call('rpush', KEYS[2], ARGV[2]);" +
"end; " +
"return ttl;",
Arrays.<Object>asList(getName(), threadsQueueName, timeoutSetName),
internalLockLeaseTime, getLockName(threadId), currentTime + threadWaitTime, currentTime);
}
throw new IllegalArgumentException();
}