如果PHP会话在30分钟后过期而没有关闭浏览器吗？

i have a comments system with an option for a user to 'report' a comment.

When clicking report the comment is simply added into a DB table.

To stop any spamming, i set a session on success.

This was aimed to only allow the user to report a comment every 24 mins.

My question is, should a session expire by itself without the need to close the browser?

Currently the session always exists unless the browser is closed.

I have checked phpinfo() and the lifetime is set to the normal 1440.

Or do i have to perhaps set the value of a session to the current time, and then check the value of the session against the current time when reporting a comment?

Thanks!

if (isset($_SESSION['LAST_ACTIVITY']) && (time() - $_SESSION['LAST_ACTIVITY'] > 1800)) {
    // last request was more than 30 minutes ago
    session_unset();     // unset $_SESSION variable for the run-time 
    session_destroy();   // destroy session data in storage
}
$_SESSION['LAST_ACTIVITY'] = time(); // update last activity time stamp

this will just clear the session