How can I ensure I have only one instance of a PHP script running via Apache?

Question

I have an index.php script that I use as a post-commit URL on a Google Code site. This script clones a directory and builds a project that may take some work.

Answer 1

how long does it take to run.

could use memcache

get( 'job_running' ) ) exit;

else $m->set( 'job_running', true );



//index code here

//at the end of the script

$m->delete( 'job_running' );

?>

If the task fails you will need to clear from memcache. Flock is a good option too... probably better actually.