[basex-talk] safe to have multiple clients call user:update-info ?

Hi, could not verify in the BaseX source code, so can I assume this is safe, since it is a file on the file system (users.xml)? Background: I want to add locking information there, so everytime an user requests to checkout a file, it should be saved there. At the same time, I have to be sure nobody else can write at the same time. Regards, Max