[GRASSLIST:9645] Re: gislock on the mapset

[Radim Blazek]

On 12/23/05, Glynn Clements <glynn at gclements.plus.com> wrote:
>
> Leonardo Lami wrote:
>
> > I have a simple question about the gislock file.
> >
> > I have the dataset of GRASS in a server and I access to it from several
> > computers link in a network.
> > I saw that if I try to access two times on the same mapset using the same user
> > from the same computer the file gislock works well and GRASS say:
> >
> > "user is currently running GRASS in selected mapset. Concurrent use not
> > allowed."
> >
> > But if I try to access two times on the same mapset using the same user from
> > an OTHER computer the file gislock does not work and I can acces with the
> > possibility to make damages.
> >
> > Is it possible or I make some errors?
>
> Which version of GRASS? 5.x or 6.x?
>
> 5.x puts the lock file in the user's home directory. The requirement
> that you have to own the active mapset prevents you from starting two
> sessions on the same mapset from the same host, but doesn't help if
> the mapset is shared between hosts.
>
> 6.x puts the lockfile in the mapset directory, so it should prevent
> the scenario which you describe. If it doesn't, that's a bug.

Unfortunately no because it checks the PID.
It is feature not bug, locking works only on one machine.
This is inherited from 5.0, I dont see big difference.
Do you have idea how to improve that so that it works over network?

Radim

> In either case, there are ways to get around the locking, e.g.
> changing MAPSET using g.gisenv directly.
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>
>