/**
* Test if we've survived through setup on at least one normal request
* without fataling.
*
* If we've made it through setup without hitting any fatals, we switch
* to render a more friendly error page when encountering issues like
* database connection failures. This gives users a smoother experience in
* the face of intermittent failures.
*
* @return bool True if we've made it through setup since the last restart.
*/
public static final function isInFlight()
{
$cache = PhabricatorCaches::getServerStateCache();
return (bool) $cache->getKey('phabricator.in-flight');
}