red "github.com/go-redis/redis"
"github.com/tal-tech/go-zero/core/logx"
const (
letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
lockCommand = if redis.call("GET", KEYS[1]) == ARGV[1] then redis.call("SET", KEYS[1], ARGV[1], "PX", ARGV[2]) return "OK" else return redis.call("SET", KEYS[1], ARGV[1], "NX", "PX", ARGV[2]) end
delCommand = if redis.call("GET", KEYS[1]) == ARGV[1] then return redis.call("DEL", KEYS[1]) else return 0 end
randomLen = 16
// 默认超时时间，防止死锁
tolerance = 500 // milliseconds
millisPerSecond = 1000
// A RedisLock is a redis lock.
type RedisLock struct {
// redis客户端
store *Redis
// 超时时间
seconds uint32
// 锁key
key string
// 锁value，防止锁被别人获取到
id string
func init() {
rand.Seed(time.Now().UnixNano())
// NewRedisLock returns a RedisLock.
func NewRedisLock(store *Redis, key string) *RedisLock {
return &RedisLock{
store: store,
key: key,
// 获取锁时，锁的值通过随机字符串生成
// 实际上go-zero提供更加高效的随机字符串生成方式
// 见core/stringx/random.go：Randn
id: randomStr(randomLen),
// Acquire acquires the lock.
// 加锁
func (rl *RedisLock) Acquire() (bool, error) {
// 获取过期时间
seconds := atomic.LoadUint32(&rl.seconds)
// 默认锁过期时间为500ms，防止死锁
resp, err := rl.store.Eval(lockCommand, []string{rl.key}, []string{
rl.id, strconv.Itoa(int(seconds)*millisPerSecond + tolerance),
if err == red.Nil {
return false, nil
} else if err != nil {
logx.Errorf("Error on acquiring lock for %s, %s", rl.key, err.Error())
return false, err
} else if resp == nil {
return false, nil
reply, ok := resp.(string)
if ok && reply == "OK" {
return true, nil
logx.Errorf("Unknown reply when acquiring lock for %s: %v", rl.key, resp)
return false, nil
// Release releases the lock.
// 释放锁
func (rl *RedisLock) Release() (bool, error) {
resp, err := rl.store.Eval(delCommand, []string{rl.key}, []string{rl.id})
if err != nil {
return false, err
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