PHP 7 Session Options
PHP 7 session_start() function can receive an array as a parameter and can override the session configuration items in php.ini.
This feature also introduces a new php.ini setting (session.lazy_write), which is set to true by default, meaning that session data is only written when it changes.
In addition to the regular session configuration directives, you can also include read_and_close options in this array. If the value of this option is set to TRUE, the session file will be closed immediately after reading, thus avoiding unnecessary file locks when the session data has not changed.
Example
Set cache_limiter to private and close it immediately after reading the session.
Instance
<?php session_start([ 'cache_limiter' => 'private', 'read_and_close' => true, ]); ?>