[GRASS-dev] Improving the G_calloc: unable to allocate xx bytes of memory message?

[Markus Neteler]

On Sat, Oct 25, 2014 at 12:13 AM, Glynn Clements
<glynn at gclements.plus.com> wrote:
> Markus Neteler wrote:
>> > r.basin map=map at Elevation prefix=o coordinates=-71.10394196,43.9865230801
>> > threshold=19005 dir=C:\\Users\\Andrea\\Basins
>> >
>> > I get:
>> > " ....
>> > v.to.rast complete.
>> > All in RAM calculation...
>> > Reading raster map <o_map_drainage_e>...
>> > Calculating basins using vector point map...
>> > Current region rows: 21612, cols: 21612
>> > ERROR: G_calloc: unable to allocate 21612 * 4 bytes of memory at io.c:41
>> ...
>>
>> Question: is there a way to also communicate in which *command* the
>> memory allocation occurred, i.e. improve the error message?
>
> Why should allocation errors be different to any other error?

That's true.

> For the case of scripts, it may suffice to fix run_command() etc so
> that they terminate (or raise an exception) if the module returns a
> non-zero exit status. If the error message is immedately followed by
> "error executing <command>", it should remove most of the ambiguity.

Yes, that would be a perfect solution to be implemented.

>> We have 9 files called "io.c" in GRASS 7.
>> Ideal would be something like:
>>
>> ERROR: G_calloc: unable to allocate 21612 * 4 bytes of memory at r.thin/io.c:41
>>
>> or
>> ERROR: r.thin: G_calloc: unable to allocate 21612 * 4 bytes of memory
>> at r.thin/io.c:41
>>
>> Not sure how to implement that in lib/gis/alloc.c
>
> alloc.c is the wrong place. If you want errors to be traceable, the
> module name should be included for *all* errors by G_fatal_error (and
> possibly others).
>
> Also, I wouldn't suggest using module/file.c, because that will be
> inaccurate (and thus misleading) if the caller is part of a library.
>
> If we just want the complete filename in allocation errors, we can
> modify the compiler switches to include $(RELDIR) as per the attached
> patch. Similarly for use of __FILE__ in the iostream headers.

Ok, I tried that patch but I don't manage to trigger it.

GRASS 7.1.svn (nc_spm_08_grass7):~ > g.region rast=elevation -p res=0.01
projection: 99 (Lambert Conformal Conic)
zone:       0
datum:      nad83
ellipsoid:  a=6378137 es=0.006694380022900787
north:      228500
south:      215000
west:       630000
east:       645000
nsres:      0.01
ewres:      0.01
rows:       1350000
cols:       1500000
cells:      2025000000000

GRASS 7.1.svn (nc_spm_08_grass7):~ > r.cost roadsmajor output=bla
start_coordinates=637500.000000,221750.000000
WARNING: segment zero_fill(): Unable to write (No such file or directory)
WARNING: Could not write segment file
ERROR: Can not create temporary file

Yet a bit unhelpful :-) It comes from lib/segment/format.c but I
didn't manage to improve that.

Markus