session - php page atomicity and consistency? -

session - php page atomicity and consistency? -

here possible scenario: php page accesses session variables session ssid 1000. on tab, user logs out,which means destroying current session. i'll assume worst case scenario happen: code still running @ page 1. happens in situation? code @ page 1 still uses session vars ssid 1000, doesn't exist now? can utilize "try catch" block handle potential exception raised ? happens session vars session ssid 1000, might using db querying @ page 1?

i know question might weird, scenario of import me because want handle exception( if situation raises exception) , prevent inconsistent values beingness inserted db.

thanks in advance

web pages stateless. not in "logged in" or "logged out" state. if session closed while i'm viewing page, attempts go on utilize session fail. $_session recreated when seek access page - new session. need web programmer handle $_session beingness empty.

php session atomicity consistency