[GRASS-dev] GRASS and QGIS on Win32, testing etc.

[Glynn Clements]

Moritz Lennert wrote:

> >> > 1. The DBF driver deadlocks randomly!
> >> > Any GRASS module that needs to access the attribute table (DBF format)
> >> > of a vector map is prone to this: E.g. I tried running v.out.ogr on a
> >> > map with ca. 3000 points repeatedly. Out of ten runs, 2 or 3 deadlock
> >> at
> >> > a random point. The task manager shows that v.out.ogr is sleeping with
> >> > 0% CPU.
> >>
> >> I can reproduce this, both with your location and in spearfish. And at
> >> first glance, it really does appear random. The only thing that I think
> >> I
> >> noticed, was that it happens more often when the machine is busy with
> >> something else. My first very wild guess would be something system
> >> resources, but as I said, this is very wild.
> >>
> >> Glynn, any hints as to where I should begin searching ?
> >
> > Run v.out.ogr under gdb; when it deadlocks, hit Ctrl-C, then type
> > "where" to get a backtrace (assuming that this works on Windows).
> 
> It does. Backtrace attached. However, I am not sure that this backtrace is
> very useful (many ??). Looking for an explanation, I found this:
> 
> http://www.cygwin.com/ml/cygwin/2006-09/msg00409.html
> 
> But maybe I have to compile with some debug option of gcc ? (gcc -g ?)

Are you using Cygwin's gdb? It doesn't work on native Windows
binaries. There is a native (MinGW) gdb at:

	http://prdownloads.sf.net/mingw/gdb-5.2.1-1.exe?download

-- 
Glynn Clements <glynn at gclements.plus.com>