抢购的实现过程

        $redis = Redis::connection();
        
        $key =  'goods_'.$id;
       // $element = null;
        $options = array(
            'cas'   => true,
            'watch' => $key,
            'retry' => 3,
        );
        $redis->transaction($options, function ($tx) use ($key, &$element) {
                $tx->multi();
                $tx->incrby($key, -1);
        });

<span style="white-space:pre">	</span>//异步队列修改库存和订单TODO