redisson分布式公平锁-释放锁原理

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[4]) then 
         redis.call('zrem', KEYS[3], firstThreadId2); 
         redis.call('lpop', KEYS[2]); 
     else 
         break;
     end; 
 end;


if (redis.call('exists', KEYS[1]) == 0) then   
    local nextThreadId = redis.call('lindex', KEYS[2], 0);   
    if nextThreadId ~= false then  
        redis.call('publish', KEYS[4] .. ':' .. nextThreadId, ARGV[1]);  
    end;  
    return 1;  
end; 
if (redis.call('hexists', KEYS[1], ARGV[3]) == 0) then  
    return nil; 
end;  


local counter = redis.call('hincrby', KEYS[1], ARGV[3], -1);  
if (counter > 0) then  
    redis.call('pexpire', KEYS[1], ARGV[2]);  
    return 0;  
end;  
    
redis.call('del', KEYS[1]);  
local nextThreadId = redis.call('lindex', KEYS[2], 0);   
if nextThreadId ~= false then  
    redis.call('publish', KEYS[4] .. ':' .. nextThreadId, ARGV[1]);  
end;  
return 1;