关于php:PHPRedisLua-实现Redis分布式锁

<?php

class locks{
    private $redis;
    protected  $lockid;    // 记录客户端加锁的 ID

    public function __construct(){$redis = new Redis();
        $redis->connect('127.0.0.1', 6379);
        $this->redis = $redis;
    }

    /**
     * @param string $name 参数名
     * @param int $exp 过期工夫
     * @param int $retry 反复次数
     * @param int $sleep  等待时间
     */
    public function lock($name = 'lock',$exp = 30, $retry = 10 , $sleep = 1){
        $result = false;
        while ($retry-- >= 0){$value  = md5(date("Y-m-d H:i:s"));
            $result = $this->redis->set($name , $value , ['NX' , 'EX'=>$exp] );
            if ($result) {$this->lockid[$name] = $value;
                echo $name.'胜利获取到锁，正在执行' . "\n";
                break;
            }
            echo $name.'加锁失败·· 失常尝试获取锁' ."\n";
            sleep($sleep);
        }
        return $result;
    }

    /**
     * @param $name
     * @return mixed
     * 删除锁
     */
    public function unlock($name){
        echo $name.'失常执行解锁···' ."\n";
        $lua = "
            local key   = KEYS[1]
            local value = ARGV[1]
            
            if(redis.call('get', key) == value)
            then
                return redis.call('del', key)
            end";

        return $this->redis->eval($lua, [$name, $this->lockid[$name]], 1);
    }

}

// 申请分布式锁
$obj = new locks();

// 执行实现申请解锁
if($obj->lock($name = "lock_1")){
    echo "执行完结，期待 5s 执行解锁操作···"."\n";
    sleep(5);
    echo "--------------------------"."\n";
    $unlockResult = $obj->unlock($name);
    if($unlockResult){echo $name.'解锁胜利··' ."\n";}
}

Redis 申请分布式锁的命令，此命令合乎原子性：

 /**
     * SET：Redis 的 String 指令
     * lock_name：锁的名称
     * unique_id：锁的惟一校验
     * NX：工夫单位
     * PX：设置过期工夫
*/

SET lock_name unique_id NX PX expire_time

别离执行，具体执行后果：

<?php
// 申请分布式锁
$obj = new locks();

// 执行实现申请解锁
if($obj->lock($name = "lock_1")){
    echo "执行完结，期待 5s 执行解锁操作···"."\n";
    sleep(5);
    echo "--------------------------"."\n";
    $unlockResult = $obj->unlock($name);
    if($unlockResult){echo $name.'解锁胜利··' ."\n";}
}

客户端 1：

客户端 2：