PHP会话不可写时抛出错误？

Is there a way to detect and throw an error if PHP session is not writable?

In a large code base, it can be difficult to know if session_write_close() was called prior to a session changing code. And when you think you are updating the session, it might be actually not writable, and this can go unnoticed.

You can check for the status of the session.

if (session_status() !== PHP_SESSION_ACTIVE) {
    //PHP 7
    throw new Error();
   }

After session_write_close() has been called the status would be PHP_SESSION_NONE