Yes, it is. If two processes attempt to create the directory simultaneously, one will succeed and the other will see that the directory has already been created. In that case, `create_directories` only returns `false` but [does not throw](http://www.boost.org/doc/libs/1_41_0/libs/filesystem/doc/reference.html) which is desired.

`dumpOneStep` is just the old name for the function that tells the `PluginConnector` to notify all plugins.