[GRASS-dev] Locking is not supported on Windows

[Paul Kelly]

On Tue, 20 May 2008 marco.pasetti at alice.it wrote:

> Hi all,
>
> there's a thing that I never understood: why Locking is not supported on Windows?
> Then:
>
> 1) what is exactly locking? I tried to find it on the programmer's manual, but without success
>
> 2) I noticed that, when opening a location/mapset, GRASS doesn't create the .gislock file, as done on linux; without the .gislock file it's impossibel to change the working environment (that is the mapset...) by the g.mapset module

Hello Marco,

If you start GRASS using grass63.bat (not grass63.sh), yes, you are 
correct that that won't work. I deliberately left it out of init.bat at 
the time I wrote it as it would have been a lot of extra work to implement 
it and it wasn't needed to get basic GRASS functionality working on 
Windows without the requirement for a Unix shell (which was my goal at the 
time). You can simply exit and restart GRASS if you want to change the 
mapset or location.

I suppose you could consider this as another example of the type of thing 
that will need to be fixed if WinGRASS is to move from alpha to 
beta-quality software.

> 3) Could you please show me the related chapter/section in the programmer's manual where I can find information about it?

I believe the facility to change mapset or location without exiting and 
restarting GRASS (and hence also this .gislock system) was added by Radim 
Blazek some time during the development of version 5.7 (which eventually 
became 6.0). So you might try searching for some old mailing list posts 
by him which might document it better. I'd risk a bet that it isn't 
documented in the programmers' manual, though it would be nice to be 
proved wrong ;)

Paul