note 49630 added to function.session-set-save-handler

For some people it might be important to know, that if the standard session handler has been overwritten with session_set_save_handler, no locking is working anymore (between session_read and session_write). The following might happen: script "A" start . read session data . . script "B" start . read session data running (30secs) add session data . write sesion data . script "B" stop write session data . script "A" stop . If a script "A" runs for a long time (say 30secs) the same user might start another script "B", which also uses a session. Script "B" will start and read session data, even though script "A" is still running. Because script "B" is much faster it will finish its work and write back its session data before script "A" has ended. Now script "A" ends and overwrites all of script "B"'s session data. If you DON'T use session_set_save_handler, this cannot happend, because in this case, PHP will not start script "B" until script "A" ends. ---- Manual Page -- http://www.php.net/manual/en/function.session-set-save-handler.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+49630 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+49630&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+49630&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+49630&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+49630&report=yes&reason=useless Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+49630&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+49630&report=yes Search -- http://master.php.net/manage/user-notes.php