使用redis乐观锁实现秒杀

header('content-type:text/html;charset=utf-8');
$redis = new Redis();
$result = $redis->open('192.168.1.236', 6379 , 5 );
$redis -> auth('likang');
//var_dump($redis -> set( 'b' , 123 ));
//
//var_dump( $redis -> get('b') );
//
//var_dump( $result );exit;
//echo "<pre>";
echo "页面被访问了" . $redis->incr('ci'). '<br>';
echo '总共抢到了' . $redis->lLen('s_kill') . '<br>';
echo '剩余数量' . $redis->get('s_kill_number'). '<br>';

$redis ->  watch('s_kill_number');

$num_ber = $redis -> get('s_kill_number');

$redis -> multi();

//print_r( $redis->lGetRange('s_kill',0 , $redis ->lLen('s_kill')));
//var_dump($num_ber);exit;

if ( $num_ber > 0) {
$redis->decr('s_kill_number');
$redis->lPush('s_kill', rand(1000, 9999));
$redis -> exec();
exit('OK'. '<br>');
} else {
$redis -> exec();
exit('抢光了'. '<br>');
}