i learned a lot about session start from my previous question. Now i'm wondering how session locking occurs when files are included in other files. Lets say i have:
page.php
include('header.php');
...some html content....
include('sub_page.php');
...more html....
header.php:
session_start();
..save session vars...
..print web page header...
sub_page.php
session_start();
...use session vars....
..print page content...
When i open page.php, does the session become unlocked as soon as header.php is done? or is it live for the whole page.php life, so sub_page's session is blocked? Is the session_start in sub_page necessary? Would it be better practice if I session_write_close every time i'm done with session data? (Though that would mean session_starting everytime i'd like to use a session variable).