use SafeApc;
// initialize
$apc = new SafeApc();
$apc->setCacheStartTime($_SERVER['REQUEST_TIME']);
$apc->setCacheVersionKey(file_get_contents('apc_version'));
// set key
$apc->set('cache key', $value, 100);
// get key (throws SafeApcNotFoundException)
$apc->get('cache key');
// delete key
$apc->delete('cache key');
change version key