php中使用redis實現秒殺

<?php
/**
 * $productTotal 商品總數
 * $productSellNum 已售商品數量
 * $currentBuyNum 當前購買數量
 */

//商品總數
$productTotal = 100;

//當前購買數量
$currentBuyNum = 5;

try {    $redis = new redis();    $result = $redis->connect('127.0.0.1',6379);    if(!$result){        throw new Exception('redis鏈接失敗');    }} catch (Exception $e){    echo $e->getMessage();    die;}//監視 product_sell_num$redis->watch('product_sell_num');//已售商品數量$productSellNum = $redis->get('product_sell_num');//判斷商品是否剩餘if($productSellNum + $currentBuyNum <= $productTotal){    $redis->multi();    $redis->set('product_sell_num',$productSellNum + $currentBuyNum);    $status = $redis->exec();    if($status){        //對購買信息處理    }else{        return "搶購失敗";    }}else{    return "搶購結束";}