On Thu, 11 Feb 2010, David Arturo Macias Corona wrote: Hi,
> Thanks, with these explanations now is more clear: > - In Linux nothing prevent two applications open file in EXCLUSIVE > from each side No. In Linux and other POSIX system there is no EXCLUSIVE mode at all. Only shared mode exists though some *nixes have kernel side support to emulated DOS DENY flags usually to implement some file servers for DOS/Windows machines. It's not standard functionality and we do not use them. > - Harbour applications can emulate EXCLUSIVE mode if them are build > with this feature It's enabled by default. > - Maybe xHarbour have same feature if it was properly copied/implemented Probably yes but I haven't tested it. > - So EXCLUSIVE may work between Harbour-xHarbour applications if > work properly in xHarbour Yes but now there are some other problems in data sharing. We have fixed CP support so it's not possible to share data with xHarbour applications which uses incompatible CP implementation. It will cause index file corruption so it's necessary to precisely verify if both application uses the same binary collation order. The same CP in both applications may not be enough. > - hbnetio is an alternative in remote environment to properly manage > EXCLUSIVE, in place of Samba It's an alternative to properly manage all types of synchronization locks not only EXCLUSIVE mode when files are accessed remotely using SAMBA, NFS, MARS or any other file server. It's also an alternative for system or network redirector limitations like maximum file size, i.e. DOS applications using HBNETIO can work with 64bit length file IO API if server running HBNETIO supports it. > I found this old subject due I was searching for "locking-scheme" to > ensure proper implementation. > Until now my conclusions are: > - Two applications, one build with Harbour and other with xHarbour > may have locking-corruption problems if each one is using a > different "locking scheme" in same RDD type > So we must to check which is default "locking-scheme" in each > compiler or force same in both Yes. But it's also true between two Harbour applications. All of them have to use exactly the same locking schemes. best regards, Przemek _______________________________________________ Harbour mailing list (attachment size limit: 40KB) Harbour@harbour-project.org http://lists.harbour-project.org/mailman/listinfo/harbour
