There are many reasons for that, here are a few of them:
A. The session file could be opened exclusively.
When the file lock is not released properly for whatever reason, it is causing session_start() to hang infinitely on any future script executions.
Workaround: use session_set_save_handler() and make sure the write function uses fopen($file, 'w') instead of fopen($file, 'x')
B. Never use the following in your php.ini file (entropie file to "/dev/random"), this will cause your session_start() to hang:
<?php
ini_set("session.entropy_file", "/dev/random");
ini_set("session.entropy_length", "512");
?>
C.
session_start() needs a directory to write to.
You can get Apache plus PHP running in a normal user account. Apache will then of course have to listen to an other port than 80 (for instance, 8080).
Be sure to do the following things:
- create a temporary directory PREFIX/tmp
- put php.ini in PREFIX/lib
- edit php.ini and set session.save_path to the directory you just created
Otherwise, your scripts will seem to 'hang' on session_start().