rengolin/HPCC-Platform — comment on commit e059ad17a92c2049a6e2cde01bd2fe0fe8fdd252
File: dali/base/dadfs.cpp line 2262
By jakesmith:

It's not thread exclusive (see other comment below) - but gives exlusive access to this IDistributedFile file, preventing other instances from modifying the properties at the same time.