[Users] [Commits] [svn:einsteintoolkit] AHFinderDirect/trunk/test/ (Rev. 1577)

[Roland Haas]

Hello all,

> If this is done by Pugh, doesn't this mask real usage of uninitialized
> memory, such that tools like valgrind cannot find potential problems?
Yes, it will do that, unfortunately. The only way around that would be
to either modify the test so that all sphericalsurfaces used have the
same nphi and ntheta, or to modify AHFinderDirect to initialize all
spherical surfaces (up to maxnphi and maxntheta) with known values so
that any garbage is wipe. This would mask only errors in AHFinderDirect.

This is not really different from what happens in Carpet if you turn on
poisoning and since it is used only for this test (via a parameter
choice) I do not really see it as an issue right now.

> Wouldn't it better not to output uninitialized values, or initialize
> them in the user thorns, not in the driver?
Not outputting them is impossible since sf_radius is a vector of 2d grid
arrays and all grid arrays in the vector need to have the same size.
Initializing in the thorn would be possible and would mean that valgrind
works (which is certainly something I would not want to lose).
Initializing in the thorn would still mask errors when the thorn itself
then tries to itself access the freshly cleared values, so there would
need to be a method to turn it off. One could think about only setting
those parts that are not used for "real" data, which however makes for
awkward code.

All in all, I would personally prefer the solution to only turn on
poisoning when needed eg in production runs and non-valgrind where I
want things to explode but to be able to turn it off so that valgrind
can catch all access to non-initialized values,

Yours,
Roland

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