/**
* Acquires a @{class:PhabricatorGlobalLock}.
*
* @return PhabricatorGlobalLock
*/
protected final function lock(PhabricatorStorageManagementAPI $api)
{
// Although we're holding this lock on different databases so it could
// have the same name on each as far as the database is concerned, the
// locks would be the same within this process.
$lock_name = 'adjust/' . $api->getRef()->getRefKey();
return PhabricatorGlobalLock::newLock($lock_name)->useSpecificConnection($api->getConn(null))->lock();
}