/* This code works */
include_once('../classes/Dispatcher.class.php');
include_once('../classes/WorkQueue.class.php');

$workQueue = new WorkQueue();
$dispatcher = new Dispatcher($workQueue);
$processlist = new ProcessList($workQueue);

$dispatcher->queueJobs();
$processlist->checkQueue();

----------------------------------------------------------------------------
/* This doesn't */

include_once('../classes/Dispatcher.class.php');
include_once('../classes/WorkQueue.class.php');

$workQueue = new WorkQueue();
$dispatcher = new Dispatcher($workQueue);
$processlist = new ProcessList($workQueue);

$pid = pcntl_fork();

if ($pid == -1) {
     die('could not fork');
} else if ($pid) {
    $dispatcher->queueJobs();
} else {
    $processlist->checkQueue();
}